switch to six for django3 compatibility (#24)

* switch to six for django3 compatibility

* update travis matrix for django3

* fix excludes

* exclude legacy py versions for django3

* python-slugify dependency  supports 2.7 and 3.5 and above only

.gitignore

@@ -55,3 +55,10 @@ docs/_build/
 
 # PyBuilder
 target/
+
+# VSCode
+/.vscode/
+
+# Pipenv
+Pipfile
+Pipfile.lock

.travis.yml

@@ -3,8 +3,7 @@ language: python
 
 python:
   - "3.5"
-  - "3.4"
-  - "3.3"
+  - "3.7"
   - "2.7"
   - pypy
 
@@ -12,6 +11,7 @@ env:
   - DJANGO="django==1.10.6"
   - DJANGO="django==1.9.12"
   - DJANGO="django==1.8.17"
+  - DJANGO="django==3.0"
 
 install:
   - pip install $DJANGO
@@ -27,12 +27,19 @@ before_script:
 
 matrix:
   exclude:
-   - python: "3.3"
-     env: DJANGO="django==1.10.6"
-   - python: "3.3"
-     env: DJANGO="django==1.9.12"
+    - python: "3.7"
+      env: DJANGO="django==1.10.6"
+    - python: "3.7"
+      env: DJANGO="django==1.9.12"
+    - python: "2.7"
+      env: DJANGO="django==3.0"
+    - python: "3.3"
+      env: DJANGO="django==3.0"
+    - python: "3.5"
+      env: DJANGO="django==3.0"
+    - python: pypy
+      env: DJANGO="django==3.0"
 
 script: coverage run --source=uuslug manage.py test
 
-after_success:
-  coveralls
+after_success: coveralls

requirements.txt

@@ -1,2 +1,3 @@
 Django>=1.8
 python-slugify>=1.2.1
+six>=1.13.0

uuslug/uuslug.py

@@ -1,6 +1,6 @@
 from django.db.models.base import ModelBase
 from slugify import slugify as pyslugify
-from django.utils import six
+import six
 if six.PY3:
     from django.utils.encoding import smart_str
 else: