Test: cts: Reimplement cts-regression in Python

[nrwahl2]

Closes T498

[nrwahl2]

Replaced commit to address feedback. The main change is the addition of a Component class.

I also removed the explicit check for executability -- we'll rely on try/except. And I removed the python equivalent of chmod a+x -- as discussed in the review, that's no longer needed.

I'm doing a little bit more testing (should be done in 30 mins or so) but I'm hoping not to touch this, except in response to any other feedback.

[nrwahl2]

I noticed the mode changed from 100755 → 100644 according to the GitHub comparison, since I started with a new file and kept the default permissions. It builds just fine without executable perms on the .in file of course. Can I leave it as 644?

[kgaillot]

I noticed the mode changed from 100755 → 100644 according to the GitHub comparison, since I started with a new file and kept the default permissions. It builds just fine without executable perms on the .in file of course. Can I leave it as 644?

Yes, that's what .in files should be

[nrwahl2]

I'm doing a little bit more testing (should be done in 30 mins or so) but I'm hoping not to touch this, except in response to any other feedback.

It's fine so far and I've done everything that comes to mind. Planning to be hands-off now.

[nrwahl2]

Minor changes:

• Made TEST_HOME a constructor param for Component, instead of a global var.
• Renamed Component.use_sudo to Component.requires_root.
• Added cmd to Component class docstring.
• Corrected type of components arg in run_components() docstring.

[nrwahl2]

New push just moves USAGE = 64 to its own line (https://github.com/ClusterLabs/pacemaker/pull/2806#discussion_r951460694).