Fixing TravisCI configuration.

[Aglezabad]

Due to continuous failures in TravisCI because my configuration is not working, I will research a way to get working. I think that Balupton (Docpad creator) have some scripts for it.

This issue will apply to 2.2.x and 2.1.x branches.

[Aglezabad]

I summon you @balupton. Could you help me with that? I don't know if I'm doing something wrong with testing. Is there any additional information about testing Docpad plugins? Thank you very much.

[Aglezabad]

In my case, this plugin is not a renderer. It adds extra calls using serverExtend function.

[Aglezabad]

docpad/docpad#1047