rename gem name

gollum-lib.gemspec

@@ -4,7 +4,7 @@ Gem::Specification.new do |s|
   s.rubygems_version = '0.0.1'
   s.required_ruby_version = ">= 1.8.7"
-  s.name              = 'gollum-lib'
+  s.name              = 'gitlab-gollum-lib'
   s.version           = '1.0.0'
   s.date              = '2013-04-02'
   s.rubyforge_project = 'gollum-lib'