Update Django GPG app

Add keyword arguments to all calls. Rename URL parameters to be
explicit ("key_id"). Add key delete view test. Update tests
to use a mixin for repeated key creation code. Grant permissions
and access the proper way using self.grant_permission and
self.grant_access.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/django_gpg/classes.py

@@ -17,6 +17,24 @@ class GPGBackend(object):
         self.kwargs = kwargs
 
 
+class KeyStub(object):
+    def __init__(self, raw):
+        self.fingerprint = raw['keyid']
+        self.key_type = raw['type']
+        self.date = date.fromtimestamp(int(raw['date']))
+        if raw['expires']:
+            self.expires = date.fromtimestamp(int(raw['expires']))
+        else:
+            self.expires = None
+        self.length = raw['length']
+        self.user_id = raw['uids']
+
+    @property
+    def key_id(self):
+        return self.fingerprint[-8:]
+    key_id.fget.short_description = _('Key ID')
+
+
 class PythonGNUPGBackend(GPGBackend):
     @staticmethod
     def _import_key(gpg, **kwargs):
@@ -136,24 +154,6 @@ class PythonGNUPGBackend(GPGBackend):
         )
 
 
-class KeyStub(object):
-    def __init__(self, raw):
-        self.fingerprint = raw['keyid']
-        self.key_type = raw['type']
-        self.date = date.fromtimestamp(int(raw['date']))
-        if raw['expires']:
-            self.expires = date.fromtimestamp(int(raw['expires']))
-        else:
-            self.expires = None
-        self.length = raw['length']
-        self.user_id = raw['uids']
-
-    @property
-    def key_id(self):
-        return self.fingerprint[-8:]
-    key_id.fget.short_description = _('Key ID')
-
-
 class SignatureVerification(object):
     def __init__(self, raw):
         self.user_id = raw['username']