Remove unused profile flags / role columns

These were made redundant by #67

db/migrate/20200425194536_remove_unused_profile_flags.rb

@@ -0,0 +1,10 @@
+class RemoveUnusedProfileFlags < ActiveRecord::Migration[5.2]
+  def change
+    remove_column :users, :admin
+    remove_column :users, :blogger
+    remove_column :users, :contributor
+    remove_column :users, :moderator
+    remove_column :users, :supporter
+    remove_column :users, :translator
+  end
+end