Automated unit testing via smalltalkci

[kurtkilpela]

Existing unit tests should be run using smalltalkci.

[kurtkilpela]

1ad4ee3 adds smalltalkci and github actions to main-v1.

[kurtkilpela]

9d31bc3 adds smalltalkci and github actions and will ultimately end up in main-v2.

[kurtkilpela]

GitHub Actions show unit test failures on macOS.

RsrConnectionSpecificationTestCase
 ✗ #testFailedAcceptOnAlternativeLocalhost (3ms)

RsrSocketStressTest
 ✗ #test10MBytes (63766ms)```

[kurtkilpela]

Replaced testFailedAcceptOnAlternativeLocalhost with testFailedConnect since the test is really about failing to connect. Updated time limit for RsrSocketStressTest to allow test10MBytes to succeed on macOS.

See #172

[kurtkilpela]

Test results are still inconsistent.

[kurtkilpela]

Additional time tweaks in 07b5126 appear to resolve tests running out of time on macOS.