[Gemfile] Point back to Core master

Gemfile

@@ -12,7 +12,7 @@ gemspec
 
 group :development do
   cp_gem 'claide',               'CLAide'
-  gem 'cocoapods-core', :git => 'https://github.com/Thomvis/Core', :branch => "issue/CocoaPods/2556"
+  cp_gem 'cocoapods-core',       'Core'
   cp_gem 'cocoapods-downloader', 'cocoapods-downloader'
   cp_gem 'cocoapods-plugins',    'cocoapods-plugins'
   cp_gem 'cocoapods-trunk',      'cocoapods-trunk'

Gemfile.lock

@@ -7,7 +7,7 @@ GIT
 
 GIT
   remote: https://github.com/CocoaPods/Core.git
-  revision: 159d93cb7576523efaf9856d069f5df23b29e646
+  revision: 10d6dc5a3615e738cd682fd05d3f658db8e53d73
   branch: master
   specs:
     cocoapods-core (0.34.1)