maintenance release
Merge pull request #39 from smartcontractkit/bugfix/error_on_rollback… …_keeps_bad_connection_in_pool If Rollback fails, txdb keeps a bad connection in the pool
Merge pull request #39 from smartcontractkit/bugfix/error_on_rollback… …_keeps_bad_connection_in_pool If Rollback fails, txdb keeps a bad connection in the pool