diff --git a/Pipfile b/Pipfile
index ee3b61b..63057b9 100644
--- a/Pipfile
+++ b/Pipfile
@@ -12,6 +12,3 @@ validators = ">=0.12.2"
 "flake8" = "*"
 setuptools = "*"
 wheel = "*"
-
-[requires]
-python_version = "3.7"
diff --git a/Pipfile.lock b/Pipfile.lock
deleted file mode 100644
index b973aae..0000000
--- a/Pipfile.lock
+++ /dev/null
@@ -1,124 +0,0 @@
-{
-    "_meta": {
-        "hash": {
-            "sha256": "2e28e1ee11aba53785a7bee2ec9b68d004035f148a7655dbdc0e537eeab9c2e3"
-        },
-        "pipfile-spec": 6,
-        "requires": {
-            "python_version": "3.7"
-        },
-        "sources": [
-            {
-                "name": "pypi",
-                "url": "https://pypi.org/simple",
-                "verify_ssl": true
-            }
-        ]
-    },
-    "default": {
-        "certifi": {
-            "hashes": [
-                "sha256:339dc09518b07e2fa7eda5450740925974815557727d6bd35d319c1524a04a4c",
-                "sha256:6d58c986d22b038c8c0df30d639f23a3e6d172a05c3583e766f4c0b785c0986a"
-            ],
-            "version": "==2018.10.15"
-        },
-        "chardet": {
-            "hashes": [
-                "sha256:84ab92ed1c4d4f16916e05906b6b75a6c0fb5db821cc65e70cbd64a3e2a5eaae",
-                "sha256:fc323ffcaeaed0e0a02bf4d117757b98aed530d9ed4531e3e15460124c106691"
-            ],
-            "version": "==3.0.4"
-        },
-        "decorator": {
-            "hashes": [
-                "sha256:2c51dff8ef3c447388fe5e4453d24a2bf128d3a4c32af3fabef1f01c6851ab82",
-                "sha256:c39efa13fbdeb4506c476c9b3babf6a718da943dab7811c206005a4a956c080c"
-            ],
-            "version": "==4.3.0"
-        },
-        "idna": {
-            "hashes": [
-                "sha256:156a6814fb5ac1fc6850fb002e0852d56c0c8d2531923a51032d1b70760e186e",
-                "sha256:684a38a6f903c1d71d6d5fac066b58d7768af4de2b832e426ec79c30daa94a16"
-            ],
-            "version": "==2.7"
-        },
-        "plac": {
-            "hashes": [
-                "sha256:879d3009bee474cc96b5d7a4ebdf6fa0c4931008ecb858caf09eed9ca302c8da",
-                "sha256:b03f967f535b3bf5a71b191fa5eb09872a5cfb1e3b377efc4138995e10ba36d7"
-            ],
-            "index": "pypi",
-            "version": "==1.0.0"
-        },
-        "requests": {
-            "hashes": [
-                "sha256:99dcfdaaeb17caf6e526f32b6a7b780461512ab3f1d992187801694cba42770c",
-                "sha256:a84b8c9ab6239b578f22d1c21d51b696dcfe004032bb80ea832398d6909d7279"
-            ],
-            "index": "pypi",
-            "version": "==2.20.0"
-        },
-        "six": {
-            "hashes": [
-                "sha256:70e8a77beed4562e7f14fe23a786b54f6296e34344c23bc42f07b15018ff98e9",
-                "sha256:832dc0e10feb1aa2c68dcc57dbb658f1c7e65b9b61af69048abc87a2db00a0eb"
-            ],
-            "version": "==1.11.0"
-        },
-        "urllib3": {
-            "hashes": [
-                "sha256:41c3db2fc01e5b907288010dec72f9d0a74e37d6994e6eb56849f59fea2265ae",
-                "sha256:8819bba37a02d143296a4d032373c4dd4aca11f6d4c9973335ca75f9c8475f59"
-            ],
-            "version": "==1.24"
-        },
-        "validators": {
-            "hashes": [
-                "sha256:172ac45f7d1944ce4beca3c5c53ca7c83e9759e39fd3fedc1cf28e2130268706"
-            ],
-            "index": "pypi",
-            "version": "==0.12.2"
-        }
-    },
-    "develop": {
-        "flake8": {
-            "hashes": [
-                "sha256:7253265f7abd8b313e3892944044a365e3f4ac3fcdcfb4298f55ee9ddf188ba0",
-                "sha256:c7841163e2b576d435799169b78703ad6ac1bbb0f199994fc05f700b2a90ea37"
-            ],
-            "index": "pypi",
-            "version": "==3.5.0"
-        },
-        "mccabe": {
-            "hashes": [
-                "sha256:ab8a6258860da4b6677da4bd2fe5dc2c659cff31b3ee4f7f5d64e79735b80d42",
-                "sha256:dd8d182285a0fe56bace7f45b5e7d1a6ebcbf524e8f3bd87eb0f125271b8831f"
-            ],
-            "version": "==0.6.1"
-        },
-        "pycodestyle": {
-            "hashes": [
-                "sha256:682256a5b318149ca0d2a9185d365d8864a768a28db66a84a2ea946bcc426766",
-                "sha256:6c4245ade1edfad79c3446fadfc96b0de2759662dc29d07d80a6f27ad1ca6ba9"
-            ],
-            "version": "==2.3.1"
-        },
-        "pyflakes": {
-            "hashes": [
-                "sha256:08bd6a50edf8cffa9fa09a463063c425ecaaf10d1eb0335a7e8b1401aef89e6f",
-                "sha256:8d616a382f243dbf19b54743f280b80198be0bca3a5396f1d2e1fca6223e8805"
-            ],
-            "version": "==1.6.0"
-        },
-        "wheel": {
-            "hashes": [
-                "sha256:9fa1f772f1a2df2bd00ddb4fa57e1cc349301e1facb98fbe62329803a9ff1196",
-                "sha256:d215f4520a1ba1851a3c00ba2b4122665cd3d6b0834d2ba2816198b1e3024a0e"
-            ],
-            "index": "pypi",
-            "version": "==0.32.1"
-        }
-    }
-}
diff --git a/portainer_cli/__init__.py b/portainer_cli/__init__.py
index 424f4f3..fd90d84 100755
--- a/portainer_cli/__init__.py
+++ b/portainer_cli/__init__.py
@@ -1,13 +1,19 @@
 #!/usr/bin/env python
-import logging
-import plac
-import json
+import os
 import re
+import logging
+import json
+import plac
 import validators
-from pathlib import Path
 from requests import Request, Session
 
-__version__ = '0.1.0'
+
+try:
+    FileNotFoundError
+except NameError:
+    FileNotFoundError = IOError
+
+__version__ = '0.2.1'
 
 logger = logging.getLogger('portainer-cli')
 
@@ -22,7 +28,7 @@ def env_arg_to_dict(s):
     }
 
 
-class PortainerCLI:
+class PortainerCLI(object):
     COMMAND_CONFIGURE = 'configure'
     COMMAND_LOGIN = 'login'
     COMMAND_REQUEST = 'request'
@@ -50,7 +56,7 @@ class PortainerCLI:
     def base_url(self, value):
         if not validators.url(value):
             raise Exception('Insert a valid base URL')
-        self._base_url = value if value.endswith('/') else f'{value}/'
+        self._base_url = value if value.endswith('/') else '{}/'.format(value)
         self.persist()
 
     @property
@@ -68,16 +74,20 @@ class PortainerCLI:
             logger.debug('using local configuration file')
             return '.portainer-cli.json'
         logger.debug('using user configuration file')
-        return Path.joinpath(Path.home(), '.portainer-cli.json')
+        return os.path.join(
+            os.path.expanduser('~'),
+            '.portainer-cli.json',
+        )
 
     def persist(self):
         data = {
             'base_url': self.base_url,
             'jwt': self.jwt,
         }
-        logger.info(f'persisting configuration: {data}')
+        logger.info('persisting configuration: {}'.format(data))
         data_file = open(self.data_path, 'w+')
         data_file.write(json.dumps(data))
+        logger.info('configuration persisted in: {}'.format(self.data_path))
 
     def load(self):
         try:
@@ -85,7 +95,7 @@ class PortainerCLI:
         except FileNotFoundError:
             return
         data = json.loads(data_file.read())
-        logger.info(f'configuration loaded: {data}')
+        logger.info('configuration loaded: {}'.format(data))
         self._base_url = data.get('base_url')
         self._jwt = data.get('jwt')
 
@@ -103,7 +113,7 @@ class PortainerCLI:
         )
         r = response.json()
         jwt = r.get('jwt')
-        logger.info(f'logged with jwt: {jwt}')
+        logger.info('logged with jwt: {}'.format(jwt))
         self.jwt = jwt
 
     @plac.annotations(
@@ -112,15 +122,20 @@ class PortainerCLI:
     )
     def update_stack(self, id, endpoint_id, stack_file='', prune=False,
                      clear_env=False, *args):
-        stack_url = f'stacks/{id}?endpointId={endpoint_id}'
+        stack_url = 'stacks/{}?endpointId={}'.format(
+            id,
+            endpoint_id,
+        )
         current = self.request(stack_url).json()
         stack_file_content = ''
         if stack_file:
             stack_file_content = open(stack_file).read()
         else:
             stack_file_content = self.request(
-                f'stacks/{id}/file?endpointId={endpoint_id}').json().get(
-                    'StackFileContent')
+                'stacks/{}/file?endpointId={}').format(
+                    id,
+                    endpoint_id,
+                ).json().get('StackFileContent')
         env_args = filter(
             lambda x: re.match(env_arg_regex, x),
             args,
@@ -145,7 +160,10 @@ class PortainerCLI:
         printc=('Print response content', 'flag', 'p'),
     )
     def request(self, path, method=METHOD_GET, data='', printc=False):
-        url = f'{self.base_url}api/{path}'
+        url = '{}api/{}'.format(
+            self.base_url,
+            path,
+        )
         session = Session()
         request = Request(method, url)
         prepped = request.prepare()
@@ -154,13 +172,13 @@ class PortainerCLI:
             try:
                 json.loads(data)
                 prepped.body = data
-            except Exception as e:
+            except Exception:
                 prepped.body = json.dumps(data)
             prepped.headers['Content-Length'] = len(prepped.body)
         if self.jwt:
-            prepped.headers['Authorization'] = f'Bearer {self.jwt}'
+            prepped.headers['Authorization'] = 'Bearer {}'.format(self.jwt)
         response = session.send(prepped)
-        logger.debug(f'request response: {response.content}')
+        logger.debug('request response: {}'.format(response.content))
         response.raise_for_status()
         if printc:
             print(response.content.decode())