Build rudimentary docker tag, instead of force
Build rudimentary docker tag, instead of force

Ansible has some shoddy detection logic for determining when to rebuild
an image or layers. I've seen issues in the past with `force: yes` and
highly recommend we peg to file hashes as an intermediate way to trigger
when to kick off a new docker image.

heartsucker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,conorsch/securedrop,heartsucker/securedrop