Show VCL in tabs

Add sphinx-php to pip requirements for building on RTD

Rename ‘Testing the Library’ to ‘Contributing’

Add JS and CS for tabs

* Make syntax highlighting resemble that of Symfony docs more.

Remove fabpot/sphinx-php from require-dev

* Now in requirements.txt

Improve styling

Add pip install to Travis

Try to fix static path on RTD

Run pip install as sudo on Travis

Make border none important

Revert path to static