Rescue within `Instance#error_build` to prevent channel close
Log before capturing error with Raven

in case the problem is with Raven
Merge pull request #109 from travis-ci/db-inst-double-rescue

Rescue during error logging to prevent channel close
Test jruby-head (and allow failures)
Merge branch 'master' into staging
Merge branch 'staging' of github.com:travis-ci/travis-worker into staging