update civis to 1.15.0 and prep release 6.3.0#79

mheilman merged 1 commit intocivisanalytics:mastercivisanalytics/datascience-python:masterfrom

mheilman:bump-civis-python-1.15.0mheilman/datascience-python:bump-civis-python-1.15.0Copy head branch name to clipboard