Fixing up repo for stable/icehouse branch

* Adding defaultbranch to .gitreview
* Removing Berksfile.lock from .gitignore
* Adding updated Berksfile.lock file
* Adding updated Gemfile.lock file
* Updating Gems
  * chef (11.12.0)

Change-Id: Ie7e430f011abf3a841f1b5a944354b02d4dd77f4
Partial-Bug: 1349154