Changes to allow testing of a full matrix in Travis CI

1. Update Appraisals, move off rc/beta releases
2. Remove .lock files from repo, so these can be rebuilt for the Ruby version being used
3. Remove explicit reference to NamedScope, just use ActiveRecord version to determine test applicability.
4. Break out the ActiveRecord and ActiveModel gemfiles by major version, so we can exclude matrix items as needed for unsupported Rubies.
5. Add JRuby ActiveRecord 4 support.

The matrix is all green, except for a set of ActiveRecord 4.0 failures that seem to be related to this issue - https://github.com/pluginaweek/state_machine/issues/248 - initial values are being set on the AR instance, but not being persisted during the intiial save.

I'm baffled, because as far as I can tell the issue should be resolved.  But nonetheless the specs are failing.  Any insight would be appreciated.