Add 4.2 gem file for running tests:

   export AR_VERSION=4.2
   bundle update active record
   bundle exec rake test:mysql2
Fixing 4.2 deprecation warning passing in an ActiveRecord object to .find rather than an id.
Replace assert_equal to assert_in_delta for time comparisons. Pulling the time back out of the DB is resulting in a second difference.
Updating import and synchronize implementations to support ActiveRecord 4.2 internal APIs while maintaining backwards compatibility with ActiveRecord 4.1.x and 3.2.x
Adding Rails 3.1 and 4.2 to the TravisCI build script.
Updating another time-oriented test to allow for a delta within 1 second.
Merge pull request #170 from zdennis/chores/activerecord-4.2

Adding support for ActiveRecord 4.2