Codecov and reporter for CI

[EricGustin]

This PR adds running the coverage tests to the GitHub Actions CI. In addition to running the coverage tests, the resulting coverage report is uploaded to codecov, and a PR bot will report any coverage changes that a given PR causes. We also now have a codecov badge for our README.md.

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (develop@dba773b). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             develop     #167   +/-   ##
==========================================
  Coverage           ?   80.51%           
==========================================
  Files              ?       57           
  Lines              ?     2910           
  Branches           ?        0           
==========================================
  Hits               ?     2343           
  Misses             ?      567           
  Partials           ?        0           

[ben-albrecht]

These changes look good to me. Any idea why the badge on your branch's README shows codecov status as 'unknown'?

[EricGustin]

Thanks @ben-albrecht
So the reason why it says unknown on my branch is because the badge is linked to CrayLabs' develop branch, so once these coverage tests are ran on develop (which wouldn't happen until after merge), then the correct coverage % should be displayed. A similar situation occurred when the coverage badge was added to SmartRedis.

[Spartee]

@EricGustin, it seems you and @al-rigazzi have figured out the bug in the one ubuntu version? the decision for now is to skip torch there and recommend users go with RAI 1.2.5 if they are block on this correct? Otherwise is this ready to go in?

[al-rigazzi]

Yeah @Spartee, it is a very specific PyTorch 1.7.1 + Python 3.9 (+ Ubuntu, possibly) problem. See e.g. this issue or one of the many other similar ones.

This was then solved in PyTorch 1.8

So yes, I'll basically repeat what you wrote, as it would be my suggestion (but @EricGustin may have changed his mind, so he'll have the last word):

• do not install torch in that CI specific matrix entry (i.e. RAI 1.2.3, Python 3.9, Ubuntu)
• start pushing users to RAI 1.2.5 (we have clues that it is more stable on other systems too)

[EricGustin]

As Al said there is a bug with Ubuntu/Python3.9/PyTorch1.7.1 which has been documented in several tickets like the one linked above. @Spartee and @al-rigazzi I've configured the Yaml file such that torch is not installed for the matrix combination Ubuntu20.04/Python3.9/RedisAI1.2.3. CI is now passing, good to merge?

[Spartee]

LGTM

[al-rigazzi]

LGTM, thanks for fixing the Pytorch/Python issue