- One unique file to list all dependencies and dependencies' versions (except Go, currently defined in `build/Dockerfile`).
- Custom versions can now be injected into Vagrant VMs.
- Vagrant dev VMs, Vagrant test VMs, and `run-integration-tests.sh` all source from `DEPENDENCIES`, to keep things 'DRY'.
- Vagrant versions can be overriden using environment variables, like it was possible in `run-integration-tests.sh`.