Fixing up repo for stable/icehouse branch

* Adding defaultbranch to .gitreview
* Removing Berksfile.lock from .gitignore
* Adding updated Berksfile.lock file
* Updating Gems
  * chef (11.12.0)
  * chefspec (4.0.0)
  * rspec (3.0.0)

Change-Id: Id343d5206bf5013df92769462fbcd34b45189506
Partial-Bug: 1349154