django: reimplement django_version_ge in pure Python

Fixes the following Python deprecation warning:
```
kobo/django/django_version.py:10: 10 warnings
tests/test_view_log.py: 24 warnings
tests/test_views.py: 6 warnings
tests/test_xmlrpc_auth.py: 8 warnings
  kobo/kobo/django/django_version.py:10: DeprecationWarning: distutils Version classes are deprecated. Use packaging.version instead.
      return LooseVersion(django.get_version()) >= LooseVersion(version_str)
```

kobo/django/django_version.py

@@ -1,10 +1,22 @@
 import django
-from distutils.version import LooseVersion
 
 def django_version_ge(version_str):
     """
     Check if current django is in higher or equal version than specified by
     version_str parameter
     """
 
-    return LooseVersion(django.get_version()) >= LooseVersion(version_str)
+    ver1 = [int(x) for x in django.get_version().split('.')]
+    ver2 = [int(x) for x in version_str.split('.')]
+
+    # lists must have the same lenght for comparison to work
+    max_len = max(len(ver1), len(ver2))
+
+    def append_zeros(lst):
+        while len(lst) != max_len:
+            lst.append(0)
+
+    append_zeros(ver1)
+    append_zeros(ver2)
+
+    return ver1 >= ver2