Use $TRAVIS_BUILD_DIR environment variable to cd into backend/frontend.
Disable glclient tests in travis.
Split test and coveralls in different lines.
Fix travis build by installing python-zope.component.

At the moment travis fails with:
  from zope.interface import named
 exceptions.ImportError: cannot import name named

I'm working around this bug (no idea where it comes from) by installing *also*
the respective debian package.
Install nodejs, and client dependencies (via npm).
Add mocha test (in GLClient) to travis.yml.

* Build a glclient package and move to the default directory as intended by
  glbackend
* Run globaleaks in development mode to prepare tests for mocha
* Run mocha.
Maybe it's python-pip to break things.

Python environments in travis are indeed virtualenvs, so we shall:
* install stuff inside virtualenv (no python-pip)
* never use sudo to install with pip