feat: Allow custom email address for inbox (#1336)

db/migrate/20201011152227_add_email_address_to_inbox.rb

@@ -0,0 +1,9 @@
+class AddEmailAddressToInbox < ActiveRecord::Migration[6.0]
+  def up
+    add_column :inboxes, :email_address, :string
+  end
+
+  def down
+    remove_column(:inboxes, :email_address)
+  end
+end