add methods for git_package and github_package

lib/cocoapods-core/podfile/dsl.rb

@@ -306,6 +306,35 @@ def pod(name = nil, *requirements)
  current_target_definition.store_pod(name, *requirements)
  end
 
+ def git_package(url, *requirements)
+ unless url
+ raise StandardError, 'A git package requires an URL.'
+ end
+
+ options = requirements.last
+ unless options.is_a?(Hash)
+ options = {}
+ requirements << options
+ end
+ options[:source] = url
+
+ name = options.delete(:name) || url.gsub(/.git$/, '').gsub(%r{^/}, '').split('/').last
+
+ unless name 
+ raise StandardError, "Could not infer pod name from '#{url}' and no `:name` was specified."
+ end
+
+ current_target_definition.store_pod(name, *requirements)
+ end
+
+ def github_package(url_fragment, *requirements)
+ unless url_fragment
+ raise StandardError, 'A GitHub package requires an URL fragment, e.g. `username/reponame`.'
+ end
+
+ git_package("https://github.com/#{url_fragment}", *requirements)
+ end
+
  # Use just the dependencies of a Pod defined in the given podspec file.
  # If no arguments are passed the first podspec in the root of the Podfile
  # is used. It is intended to be used by the project of a library. Note: