added docker file to support experimenter full stack docker instance

[jaredlockhart]

@tiftran Here I think this will help:

https://github.com/mozilla/ci-docker-bases/#therapist

[tiftran]

@jaredkerim not sure if this was what you meant

[jaredlockhart]

bors r+

[bors[bot]]

Build succeeded

• ci/circleci: build
• ci/circleci: docs
• ci/circleci: lint
• ci/circleci: test