If PR title has `[ci: last-only]`, only test last commit
If PR title has `[ci: last-only]`, only test last commit

adriaanm/scabot,adriaanm/scabot,scala/scabot,SethTisue/scabot,scala/scabot,SethTisue/scabot,SethTisue/scabot,adriaanm/scabot