Ensure that Moped and Moped::BSON is defined before testing against Moped::BSON::ObjectID

In my environment we had an issue where ap was causing sidekiq to blow up because apparently our moped is not eager loading Moped::BSON.  Moped was present.
Merge pull request #130 from Velkitor/master

Ensure that Moped and Moped::BSON is defined before testing against Mope...