Unpin the coverage dependency

Context

The coverage dependency is currently pinned to version 4.4.0 due to crashes experienced with 4.4.2. A few more versions have been released since then, dependency should be unpinned if possible.

Task Description

Test local and CI coverage report generation with coverage > 4.4.2.
Unpin coverage requirement if possible.

Acceptance Criteria

Coverage version 4.4.0 is not a hard requirement anymore.

Edited Oct 30, 2018 by Martin Blanchard