- python-arpy is unobtainable via pacman
  - Also a minor change to how we display install instructions
  from Fedora's dnf package manager

Change install instructions for python-arpy package on Arch

See merge request !614

This is to address #471 that
documented unhelpfull behavour when tracking git sources.

Add warning to git track if track and ref are not present

Closes #471

See merge request !580

This reverts commit 4f168b9b.

The latest version of pytest_pylint works fine with pylint 2, which
means there is no longer a reason to restrict the pylint version.

pylint 2 is required for Python 3.7.

Do not rely on `StopIteration` bubbling up.

https://www.python.org/dev/peps/pep-0479/

Python 3.7 support

See merge request !615

.gitlab-ci.yml: Remove unused script "install.sh"

See merge request !617

The tmp directory is filled when adding an artifact with temporary
files. This causes problems on calculate_cache_size() because we could
try to a attemp to do a stat() on a temporary file that meanwhile has
been reaped.

Handle this by not considering the tmp directory when calculating the
cache size.