Fixed MacOS compatibility

[GlassOfWhiskey]

This commit fixes support for MacOS X operating system. In particular it fixes the following bugs:

• On MacOS X, temporary directory can be a symbolic link. This commit explicitly derives the real path when creating a temporary folder;
• On MacOS X, the default version of sh is quite old and doesn't support all command features. This commit explicitly invokes bash shell on darwin systems.
• The CWL translator was mounting the host StreamFlow workdir with a bind mount to the same path in a Docker container. Now the folder in the container is always configured as /tmp/streamflow.

In addition, this commit sets up a Mac OS X runner to perform automatic CI unit tests and CWL conformance tests when submitting PRs.

[codecov-commenter]

Codecov Report

Patch coverage: 92.30% and project coverage change: +0.02 🎉

Comparison is base (802fd42) 65.52% compared to head (1d58667) 65.54%.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #77      +/-   ##
==========================================
+ Coverage   65.52%   65.54%   +0.02%     
==========================================
  Files          73       73              
  Lines        8724     8738      +14     
  Branches     2072     2076       +4     
==========================================
+ Hits         5716     5727      +11     
- Misses       2652     2653       +1     
- Partials      356      358       +2     

Impacted Files	Coverage Δ
streamflow/recovery/checkpoint_manager.py	77.14% <ø> (ø)
streamflow/deployment/connector/local.py	72.91% <66.66%> (-0.90%)	⬇️
streamflow/core/deployment.py	92.23% <100.00%> (ø)
streamflow/core/utils.py	73.58% <100.00%> (ø)
streamflow/cwl/processor.py	86.91% <100.00%> (+0.26%)	⬆️
streamflow/cwl/translator.py	87.68% <100.00%> (ø)
streamflow/deployment/connector/base.py	88.00% <100.00%> (+0.19%)	⬆️
streamflow/deployment/connector/container.py	58.99% <0.00%> (-1.33%)	⬇️
streamflow/data/data_manager.py	87.34% <0.00%> (-0.61%)	⬇️
streamflow/data/remotepath.py	70.24% <0.00%> (+2.43%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.