Update checksum for docker binary archive (#937)
Update checksum for docker binary archive (#937)

The checksum added by #928 doesn't match that for:
https://download.docker.com/linux/static/stable/x86_64/docker-17.09.0-ce.tgz

...so was resulting in packer-build failures:
https://travis-ci.org/travis-infrastructure/packer-build/jobs/298683570#L1834

Fixes #936.
ljharb/travis-cookbooks,travis-ci/travis-cookbooks,travis-ci/travis-cookbooks,spurti-chopra/travis-cookbooks,ljharb/travis-cookbooks,spurti-chopra/travis-cookbooks,ljharb/travis-cookbooks,spurti-chopra/travis-cookbooks,travis-ci/travis-cookbooks