remove duplicate build runs in travis. These extra runs were used to

test identity map and not fully removed when the feature was removed.

ci/travis.rb

@@ -100,9 +100,6 @@ ENV['GEM'].split(',').each do |gem|
     build = Build.new(gem, :isolated => isolated)
     results[build.key] = build.run!
 
-    if build.activerecord?
-      results[build.key] = build.run!
-    end
   end
 end