Adds information to the README about getting the tests to run
Updates to be compatible with Rails 4.

* Updates the activerecord dependency
* Changes ActiveRecord::Base::ConnectionSpecification to ActiveRecord::ConnectionAdapters::ConnectionSpecification. This was changed in rails commit dae7b6545372cba40e08554b9a7b2f391eaa5c6e
Merge remote-tracking branch 'origin/rails4'