Add a unit test to highlight that loose trigger is bad
Add a unit test to highlight that loose trigger is bad

Prowjob trigger is interpreted as regex, a loose regex means a prow job can be triggered unexpectedly.

cjwagner/test-infra,BenTheElder/test-infra,jessfraz/test-infra,kubernetes/test-infra,dims/test-infra,BenTheElder/test-infra,cjwagner/test-infra,cblecker/test-infra,michelle192837/test-infra,cjwagner/test-infra,jessfraz/test-infra,jessfraz/test-infra,cjwagner/test-infra,dims/test-infra,cblecker/test-infra,michelle192837/test-infra,michelle192837/test-infra,dims/test-infra,kubernetes/test-infra,jessfraz/test-infra,jessfraz/test-infra,BenTheElder/test-infra,cjwagner/test-infra,dims/test-infra,jessfraz/test-infra,michelle192837/test-infra,dims/test-infra,michelle192837/test-infra,kubernetes/test-infra,cblecker/test-infra,kubernetes/test-infra,kubernetes/test-infra,cjwagner/test-infra,cblecker/test-infra,michelle192837/test-infra,dims/test-infra,BenTheElder/test-infra,kubernetes/test-infra,cblecker/test-infra,cblecker/test-infra,BenTheElder/test-infra,BenTheElder/test-infra