Refactor ChefSpec tests

Change-Id: I015d59f5d7f929bd421846f50e1b7a8ad5156248
Implements: blueprint refactor-spec-files
Fix the depends cookbook version issue in metadata.rb

The depends condition should be ether of below:
depends 'cookbook-name', '>=x.y.z'
depends 'cookbook-name', '~>x.y'

Change-Id: I1e60d3c2e5e7fadd45af6e75a74719992b4e4971
Closes-bug: 1300524
Merge "Refactor ChefSpec tests"
Use consistent hash type in Berksfile

This change uses consistent hash types in the Berksfile. Before
there were two different assignments:
  cookbook "statsd",
    :git => "git://github.com/att-cloud/cookbook-statsd.git"
  cookbook "openstack-common",
    git: "git://github.com/stackforge/cookbook-openstack-common.git"

This fixes that issue so they are both consistent.

Change-Id: Id20e2249b1f00a4abd90639243e4a1e600a64c47