general: stack

* coveralls
* travis
* sphinx
* tox
* pytest

EDIT: changed to pytest

Signed-off-by: Mateusz Susik <mateusz.susik@cern.ch>
Specifying the interval range has one major drawback and you already gave the example above - sometimes a files is not touched the whole year - then that very year should be not included in the copyright line. I myself would prefer the more verbose listing of the years at all times, in order to prevent including a skipped year.

The inconsistency is mainly between the LICENSE file and all others.