Add admin capcodes

Sometimes, it is necessary for an admin or other moderator to reveal
themselves. Capcodes allow them to do so by appending a special colored
portion at the end of their name on a post.

This adds object-level permissions, so if you have a moderator who
shouldn't be able to use the "admin" capcode, you can give them
permission only to the "moderator" capcode.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

Pipfile

@@ -9,6 +9,7 @@ pillow = "*"
 django-hcaptcha = "*"
 django-environ = "*"
 django-guardian = "*"
+django-colorfield = "*"
 
 [dev-packages]
 mypy = "*"