(PDB-435) Travis no longer has bundler installed by default, now
installing it explicitly
Merge pull request #842 from senior/ticket/1.5.x/fix-travis-bundler-issue

(PDB-435) Travis no longer has bundler installed by default, now installing it explicitly
Merge remote-tracking branch 'upstream/1.5.x' into 1.6.x

* upstream/1.5.x:
  (PDB-435) Travis no longer has bundler installed by default, now installing it explicitly
Merge remote-tracking branch 'upstream/1.6.x'

* upstream/1.6.x:
  (PDB-435) Travis no longer has bundler installed by default, now installing it explicitly