"cherrypick" fix for first commit

Commit should be last. This was taken from the parent repo.

Author: Ilya Radchenko

lib/webhooks.js

@@ -46,7 +46,7 @@ function startFromCommit(project, payload, send){
 // returns : {trigger, branch, deploy}
 function pushJob(payload){
     var branchname,
-        commit = payload.commits[0],
+        commit = payload.commits[payload.commits.length - 1],
         trigger,
         ref;
 
@@ -97,4 +97,4 @@ function receiveWebhook(emitter, req, res){
     function sendJob(job) {
         emitter.emit('job.prepare', job)
     }
-}
+}