Add CI setup scripts

A move towards scripting the setup of CI boxes:

* Add upstart script with default configuration
* Mount 32G tmpfs at `/opt/flynn-test/build`
* Build rootfs + kernel into `/opt/flynn-test/build`
* Install Flynn CLI into `/opt/flynn-test/bin`
* Put BoltDB in `/opt/flynn-test/flynn-test.db`
* Copy test apps into `/opt/flynn-test/apps`
* Run VMs as `flynn-test` user