Allow an object to #becomes a non-Enumerize model.

lib/enumerize/activerecord.rb

@@ -58,6 +58,8 @@ def write_attribute(attr_name, value, *options)
       # Support multiple enumerized attributes
       def becomes(klass)
         became = super
+        return became unless became.respond_to?(:enumerized_attributes)
+
         klass.enumerized_attributes.each do |attr|
           # Rescue when column associated to the enum does not exist.
           begin

test/activerecord_test.rb

@@ -521,6 +521,25 @@ def self.name
     expect(user.interests).must_equal uniq_user.interests
   end
 
+  it 'allows an object to #becomes a non-Enumerize model' do
+    class NonEnumerizeUser < ActiveRecord::Base
+      self.table_name = "users"
+    end
+
+    class EnumerizeUser < NonEnumerizeUser
+      extend Enumerize
+
+      enumerize :role, in: [:admin, :ghost]
+    end
+    EnumerizeUser.delete_all
+
+    user = EnumerizeUser.create(role: :admin)
+    expect(user.role).must_equal 'admin'
+
+    non_enumerize_user = user.becomes(NonEnumerizeUser)
+    expect(non_enumerize_user).must_be :valid?
+  end
+
   it "doesn't update record" do
     Document.delete_all