chore: rubocop

chore: fix api test conventions

chore: rubocop -A spec/

chore: more rubocop -A

fix failing test

rubocop fixes

removes helper methods that are in my opinion dead code

more rubocop fixes

rubocop -a --auto-gen-config

db/migrate/20140921104907_remove_stale_memberships.rb

@@ -1,5 +1,5 @@
 class RemoveStaleMemberships < ActiveRecord::Migration[4.2]
   def up
-    Membership.where("group_id NOT IN (?)", Group.ids).delete_all
+    Membership.where.not(group_id: Group.ids).delete_all
   end
 end