Implemented Github Actions for Mac and Added Mac Compatibility

[steel-bucket]

• Added Mac compatibility
• Added Actions which builds and tests the code for Mac.
• For Mac it was simple, as it's unix based, I just had to make the test_continuous_output_does_not_timeout time to 5 seconds instead of 3.

[cfsmp3]

Why do we need this change?

[steel-bucket]

Somehow not running without it

[steel-bucket]

Should I do some research?

[cfsmp3]

Should I do some research?

Yes, we can't merge something without understanding what's going on :-)

[steel-bucket]

Okay

[steel-bucket]

@cfsmp3 Okay, so I did some research. First I thought that the problem was that "sleep" was taking slightly more time in macos. So I tried with bash and zsh, but they didn't work. Then I tried to perform the timing before the draining, that didn't work. Then I started looking for the functions that may be different for Linux and Mac in the code and not just in the tests. I thought the libc::setpgid would be the difference so I tried replacing it with nix::unistd::setpgid, but that didn't work either, and debugging showed that the duration is unchanged after setpgid.

So now, the thing that I'm almost sure of is that the slight time change originates from the killpg function, so I guess Mac takes slightly more time killing the application.

I've modified the tests for asserting different duration for Linux and Mac. Please suggest any changes.
Thank you.