[Bundle] Use Core from mr-dsl-project-directive

Gemfile

@@ -17,7 +17,7 @@ gem 'json', :git => 'https://github.com/segiddins/json.git', :branch => 'seg-1.7
 
 group :development do
   cp_gem 'claide',                'CLAide'
-  cp_gem 'cocoapods-core',        'Core'
+  cp_gem 'cocoapods-core',        'Core',                 'mr-dsl-project-directive'
   cp_gem 'cocoapods-deintegrate', 'cocoapods-deintegrate'
   cp_gem 'cocoapods-downloader',  'cocoapods-downloader'
   cp_gem 'cocoapods-plugins',     'cocoapods-plugins'

Gemfile.lock

@@ -7,8 +7,8 @@ GIT
 
 GIT
   remote: https://github.com/CocoaPods/Core.git
-  revision: 28418bb448a7b5712cd196fed70d72778af0d128
-  branch: master
+  revision: d3db81bb0dba19299767b31898e99483921d5194
+  branch: mr-dsl-project-directive
   specs:
     cocoapods-core (1.0.0.beta.2)
       activesupport (>= 4.0.2)