Check for unknown permissions

This guards against anyone mispelling or using the wrong words for a
permission, which could introduce unexpected or hard to catch errors.

app/notify_client/models.py

@@ -1,3 +1,4 @@
+from itertools import chain
 from flask_login import UserMixin, AnonymousUserMixin
 from flask import session
 
@@ -9,6 +10,8 @@ roles = {
     'manage_api_keys': ['manage_api_keys']
 }
 
+all_permissions = set(chain.from_iterable(roles.values())) | {'view_activity'}
+
 
 class User(UserMixin):
     def __init__(self, fields, max_failed_login_count=3):
@@ -101,6 +104,11 @@ class User(UserMixin):
 
     def has_permissions(self, *permissions, any_=False, admin_override=False):
 
+        unknown_permissions = set(permissions) - all_permissions
+
+        if unknown_permissions:
+            raise TypeError('{} are not valid permissions'.format(unknown_permissions))
+
         # Only available to the platform admin user
         if admin_override and self.platform_admin:
             return True