This should let me finish getting the docs build back online. IPython is now a dependency for building the docs.
This closes #1428.
And actually IPython has always been needed to build the docs properly, so this isn't a new dependency.
MAINT: Use ip_directive shipped with IPython. Closes #1428.
DOC: Make optional IPython dependency explicit
Works for me locally. I'm going to merge this, so I can see if the auto-doc build is fixed.
Coverage remained the same when pulling 4f69a5d on jseabold:import-ipython-directive into 07576e4 on statsmodels:master.