wikicloth doesn't pin dependencies so we have to

Author: kivikakk

github-markup.gemspec

@@ -24,4 +24,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'nokogiri', '1.6.8.1'
   s.add_development_dependency 'nokogiri-diff', '~> 0.2.0'
   s.add_development_dependency "github-linguist", "~> 6.0"
+  s.add_development_dependency "twitter-text", "~> 1.14"
 end