fix: Fix install (included missing VERSION)

Refs #637

.versionrc.json

@@ -4,7 +4,7 @@
   "repository": "django-modeltranslation",
   "bumpFiles": [
     {
-      "filename": "modeltranslation/VERSION",
+      "filename": "VERSION",
       "type": "plain-text"
     }
   ]

MANIFEST.in

@@ -1,3 +1,4 @@
-include *.txt *.rst
+include *.txt *.rst VERSION
+prune modeltranslation/tests
 recursive-include docs *.rst conf.py Makefile make.bat
 recursive-include modeltranslation/static *

modeltranslation/__init__.py

@@ -8,4 +8,4 @@ try:
 except ImportError:
     pass
 
-__version__ = (Path(__file__).parent / "VERSION").open().read().strip()
+__version__ = (Path(__file__).parent.parent / "VERSION").read_text().strip()