Add a pytest based testing framework and tests for build

[ganesh-k13]

Changes

• Add a pytest based testing framework
• Add tests for
  • --version
  • build

Notes

• part of Improve unit testing using frameworks #154
• I'll club the relevant commands and raise PRs to not bloat one single big bang PR.
• Additionally, the faster this goes in, we need not maintain tests in two places, i.e. spin/tests and .github/workflows/test.sh

[stefanv]

Thanks, this is a great start! After merging #159 tomorrow, I'll get this in, and then spend some time porting the tests (unless someone beats me to it!).

[ganesh-k13]

Thanks @stefanv! No worries :) I'll try to port all the tests, just wanted to ensure I'm on the right track.

[stefanv]

@ganesh-k13 @jarrodmillman Can you take a look? I think this is ready now.

[ganesh-k13]

Thanks @stefanv ! I was away for a few weeks.

[stefanv]

Thanks for getting this started, @ganesh-k13!