travis: removal of Python 2.6

* Removing python 2.6 from the test matrix as it times out.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
linkbacks: fix external url creation

* Amends 4755a50867bd34a8debb4b87d952e72b931eefbc.  (addresses #1707)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
workflows: hotfix unittest

* Improves tests stability.

* Simplifies workflow engine.

* Fixes the endlessy working workflow engine bug.

* Reduces log produces by workflows unit tests.

* Inverts arguments in test to expected val, current val.

Signed-off-by: Guillaume Lastecoueres <guillaume.lastecoueres@cern.ch>
Co-authored-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
Reported-by: Yoan Blanc <yoan.blanc@cern.ch>