merge omg-js-testrunner to this repo

[boolafish]

Note

Merging the https://github.com/omgnetwork/omg-js-testrunner repo to here as the remaining function of that repo is a simple docker file that wraps omg-js.

• add docker file for omg-js
• publish the image as testrunner to GCP registry
• setup GCLOUD_SERVICE_KEY in circle CI env var

Test

• example job: link
• example image: link