remove '.' from the end of urls. (#457)
remove '.' from the end of urls. (#457)

* remove '.' from the end of urls.

* review comments

* flake

craigcitro/pydatalab,googledatalab/pydatalab,supriyagarg/pydatalab,craigcitro/pydatalab,yebrahim/pydatalab,yebrahim/pydatalab,craigcitro/pydatalab,googledatalab/pydatalab,yebrahim/pydatalab,supriyagarg/pydatalab,supriyagarg/pydatalab,googledatalab/pydatalab