Initial pass at travis config file.

Trying to install jekyll dependencies and run a jekyll build.
Using source directive for travis in jekyll config.
Setting UTF-8 US encoding in travis environment.
Adding IRC notifications from Travis-CI.
Excluding /vendor in jekyll config.

Works around a build bug in Travis (hopefully).
Updated the exclude in jekyll config.

It must be in array format.
Merge pull request #7 from rhyolight/add-travis

Initial pass at travis config file.