Remove unused groups from simplecov's profile

lib/simplecov_custom_profile.rb

@@ -3,11 +3,8 @@ require 'simplecov'
 SimpleCov.profiles.define 'gem' do
   add_filter '/test/'
   add_filter '/features/'
-  add_filter '/spec/'
   add_filter '/autotest/'
 
   add_group 'Binaries', '/bin/'
   add_group 'Libraries', '/lib/'
-  add_group 'Extensions', '/ext/'
-  add_group 'Vendor Libraries', '/vendor/'
 end