Travis: Run cucumber tests

We never ran the full cucumber test suite with Travis-CI. This PR ensures that all tests are run, so we can verify pull requests do not fail tests before merging.

This pull request:

Runs Travis with Ubuntu 16.04 due to various problems with 14.04 (https://github.com/travis-ci/travis-ci/issues/8906)
Runs the cucumber tests with Travis
Uses /bin/echo instead of inbuilt shell echo command for running tests
Uses the OBS repo for the neamon packages instead of the consol.de ones

naemon / naemon-livestatus

Travis: Run cucumber tests #36