build(python): remove python 3.7 from kokoro Dockerfile#762

tseaver merged 1 commit intomastergoogleapis/python-bigquery:masterfrom

owl-bot-update-lock-5ff7446edeaede81c3ed58b23a4e76a5403fba1350ce28478045657303b6479dgoogleapis/python-bigquery:owl-bot-update-lock-5ff7446edeaede81c3ed58b23a4e76a5403fba1350ce28478045657303b6479dCopy head branch name to clipboard