Add project_urls to setup
Add project_urls to setup

These are used by PyPI and other services.

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