Add various GitHub environment variables (#604)

* define GITHUB_ACTION_PATH #603

* Add more environment variables

* Add job name

Note: the job name gets a suffix for matrix builds, but this is not part of the env var

* fix: remove unnecessary variables

* feat: add `RepositoryOwner`

credit: @KnisterPeter

* feat: add test for `getGithubContext()`

Co-authored-by: Ryan (hackercat) <me@hackerc.at>

pkg/runner/runner.go

@@ -116,6 +116,7 @@ func (runner *runnerImpl) NewPlanExecutor(plan *model.Plan) common.Executor {
 
 			for i, matrix := range matrixes {
 				rc := runner.newRunContext(run, matrix)
+				rc.JobName = rc.Name
 				if len(matrixes) > 1 {
 					rc.Name = fmt.Sprintf("%s-%d", rc.Name, i+1)
 				}