Fixed dependency on configobj

Importing mpltools in setup.py causes python to 
attempt to import configobj before setuptools has
a chance to resolve and install the dependency on 
configobj. Since the import was only done for the
version variable, I hardcoded it in setup.py
Added Travis build script, including minimal test

Modified examples/plot_all_styles.py to make sure
it works on a headless environment (such as a 
Travis build)
Added Travis build script, including minimal test

Modified examples/plot_all_styles.py to make sure
it works on a headless environment (such as a 
Travis build)
Merge pull request #21 from marcusps/configobj-dep-fix

configobj dep fix