add bors to ink repo (#357)

* add bors to ink repo

* travis fails on a *.tmp branch; turned off 'build pushed branches' from config and set only 'master' here because travis anyways runs on PRs

* statuses reviewed, reordered

* less statuses, longer timeout (10 min didn't work)
15 jobs for master in 9 minutes and 11 seconds (queued for 2 seconds)