Need bundle install before generating master docs

Author: eregon

support/generate_docs.rb

@@ -34,6 +34,9 @@ def sh(*args)
 end
 
 sh "git", "checkout", "master"
+
+sh "rm", "-f", "Gemfile.lock"
+sh "bundle", "install"
 sh "bundle", "exec", "rake", "yard"
 
 versions.each do |version|