update gang name if already exists

db/migrate/20201007213411_add_initial_gang_and_connect_to_homies.rb

@@ -1,8 +1,9 @@
 class AddInitialGangAndConnectToHomies < ActiveRecord::Migration[5.2]
   def up
-    # execute "INSERT INTO gangs SELECT 'name' WHERE NOT EXISTS (SELECT * FROM gangs)"
     if Gang.count.zero?
       Gang.create(name: 'Default').save
+    elsif Gang.count == 1
+      Gang.update name: 'Default'
     end
     gang = Gang.first