Change TravisCI links to GitHub Actions

Author: justdave

contributing/developer.md

@@ -76,10 +76,10 @@ When you fix a bug, ask yourself:
 ## Test Suite
 
 Nothing will get checked into Bugzilla that doesn't pass the test suite.
-The test suite is automatically executed on each commit by the [Travis
-CI](https://travis-ci.org/bugzilla/bugzilla) system to warn us of bad
-code. It is using Bugzilla's [GitHub
-mirror](https://github.com/bugzilla/bugzilla). Anything that fails to
+The test suite is automatically executed on each commit by
+[GitHub Actions](https://github.com/bugzilla/harmony/actions) system to
+warn us of bad code. It is using Bugzilla's [GitHub
+repository](https://github.com/bugzilla/harmony). Anything that fails to
 pass the testing suite will be backed out immediately.
 
 The test suite continues to expand to detect more problems as the