feat(screenshot): Add a gulp to compare screenshot diffs, upload results to gcs & firebase - #2774

feat(screenshot): Add a gulp to compare screenshot diffs, upload results to gcs & firebase#2774

mmalerba merged 16 commits into

angular:masterangular/components:masterfrom

tinayuangao:screenshot-pr-upload-comparetinayuangao/material2:screenshot-pr-upload-compareCopy head branch name to clipboard