Bazel continous integration setup

This workspace contains the setup for the continuous integration system of Bazel. This setup is based on docker images built by bazel.

Make sure you have a Bazel installed with a recent enough version of it. Also make sure gcloud and docker are correctly configured on your machine. Only docker version 1.10 or later is supported.

More documentation:

• init.sh: initializes the whole CI platform. This may delete VMs and do other irreversible changes, so handle with care.
• vm.sh: lets you control the machines (e.g. start/stop them, create/delete/reimage them), including the Jenkins controller and the executor nodes.
• workflow: explains the CI workflow, and how you can test local changes with jenkins-staging
• jobs: explains what jobs are running on the CI
• user: explains how to use the CI system for a Bazel contributor.