Ok, we could actually run tests with Rails 4 now. Still a lots of failures.
Fix test for rails 4 by using real data instead of stubbing connections calls
Since we have switched to mysql2 gem for new versions of rails, let's not statically define connection info in the spec and pull it from AR configuration
Rails4 deprecation warnings fixing
Do not define db adapter in tests, use AR config
Update multi-db migrations code to work with Rails 4 new command recorder
Switch back to mysql gem because rails 3.0 does not support mysql2
Test with rails 4
Freeze mysql gem version for rails 3.0
Freeze mysql gem version for rails before 4.0