- activate travis ci build by adding .travis.yml file

For the slick test of postgres and mysql there running server needed.
The travis build will install a postgres database and i guess a mysql is already
available.

The pre installed version of mysql and postgres on travis are configured with blank passwords.
The user for mysql is root (full rights) and for postgres is postgres.

Set postgres.password and mysql.password to empty string because otherwise there ocuur a NullPointerException in slick testkit.

The build on travis ci hangs when test mysql and postgres are performed
- added new simple jdbc connection test for mysql and postgres in the MigrationSeqTest

Added a simple test for mysql and postgres that open a jdbc connection and execute Select 1.
This test should ensure that there is a running mysql and postgres instance and a jdbc connection
can established to them. This two new test help to solve the hanging build on travis.
- activate coveralls integration

After the hanging travis build problem was solved than activate coveralls by define
the script command in the .travis.yml file with sbt coveralls command.