DOC/BLD : build docs from source
DOC/BLD : build docs from source

 - build the docs from the source, not installed code
 - add mocks so external dependencies don't need to be installed

giltis/scikit-xray,licode/scikit-xray,licode/scikit-xray,tacaswell/scikit-xray,scikit-xray/scikit-xray,CJ-Wright/scikit-beam,danielballan/scikit-xray,CJ-Wright/scikit-beam,giltis/scikit-xray,Nikea/scikit-xray,scikit-xray/scikit-xray,ericdill/scikit-xray,tacaswell/scikit-xray,tacaswell/scikit-beam,Nikea/scikit-xray,danielballan/scikit-xray,ericdill/scikit-xray,hainm/scikit-xray,licode/scikit-beam,celiafish/scikit-xray,licode/scikit-xray,tacaswell/scikit-beam,celiafish/scikit-xray,ericdill/scikit-xray,licode/scikit-beam,tacaswell/scikit-xray,CJ-Wright/scikit-beam,scikit-xray/scikit-xray,hainm/scikit-xray,tacaswell/scikit-beam,Nikea/scikit-xray,licode/scikit-beam,yugangzhang/scikit-beam,giltis/scikit-xray,celiafish/scikit-xray,yugangzhang/scikit-beam,yugangzhang/scikit-beam,danielballan/scikit-xray,hainm/scikit-xray