BLD: Only unshallow when required
BLD: Only unshallow when required

Only run unshallow when required, which is usually on master

josef-pkt/statsmodels,jseabold/statsmodels,bashtage/statsmodels,bashtage/statsmodels,statsmodels/statsmodels,josef-pkt/statsmodels,jseabold/statsmodels,statsmodels/statsmodels,statsmodels/statsmodels,jseabold/statsmodels,jseabold/statsmodels,statsmodels/statsmodels,josef-pkt/statsmodels,josef-pkt/statsmodels,bashtage/statsmodels,bashtage/statsmodels,bashtage/statsmodels,josef-pkt/statsmodels,bashtage/statsmodels,statsmodels/statsmodels,jseabold/statsmodels,josef-pkt/statsmodels,statsmodels/statsmodels