Added TravisCI config file

Compiles using all modes, runs unit tests and runs all cookbook recipe
scripts. Had to remove `pylab.show()` from plot scripts in cookbook to
be able to run scripts.
Install missing libs in Travis config

Forgot to install numpy and matplotlib and the required 32bit libraries
for cross-compiling.
Added Travis badge to README
Forgot 'python-' in Ubuntu lib names for Travis
Set PATH to build dir in Travis
Disable Travis email notifications
Trying out env command in Travis

Set PATH using Travis env variables to see is running cookbook recipes
works.
Install mpl basemap on Travis build
Try setting matplotlib to use Agg backend

Getting error in Travis when using the default tk backend.
Using matplotlib env variable to set rc path

Setting it to Travis home and putting rc file there.
Outsource echo command in travis to a bash file
Merge pull request #4 from leouieda/travis

Add TravisCI support