ENH: Add google analytics to docs
ENH: Add google analytics to docs

This way we can actually see what of our docs is being used.

dopplershift/MetPy,Unidata/MetPy,dopplershift/MetPy,ShawnMurd/MetPy,ahaberlie/MetPy,Unidata/MetPy,jrleeman/MetPy,ahaberlie/MetPy,jrleeman/MetPy