lxml workaround

[natevw]

To install the Python dependencies on a somewhat clean Yosemite machine I had to do the following:

sudo easy_install pip
sudo STATIC_DEPS=true pip install Cheetah lxml matplotlib numpy scipy docutils sphinx

…specifically the STATIC_DEPS flag via this StackOverflow answer to avoid an error installing lxml:

fatal error: 'libxml/xmlversion.h' file not found