* alloc_runner
* Random tests
* parallel task_runner and no exec compatible check
* Parallel client
* Fail fast and use random ports
* Fix docker port mapping
* Make concurrent pull less timing dependant
* up parallel
* Fixes
* don't build chroots in parallel on travis
* Reduce parallelism on travis with lxc/rkt
* make java test app not run forever
* drop parallelism a little
* use docker ports that are out of the os's ephemeral port range
* Limit even more on travis
* rkt deadline
Cleanup can be used for cleaning up resources created by drivers to run
a task. Initially the Docker driver is the only user (to remove
downloaded images).
The Driver.Prestart method currently does very little but lays the
foundation for where lifecycle plugins can interleave execution _after_
task environment setup but _before_ the task starts.
Currently Prestart does two things:
* Any driver specific task environment building
* Download Docker images
This change also attaches a TaskEvent emitter to Drivers, so they can
emit events during task initialization.
Since lxc support requires linking to a C lib at compile and runtime
I'm putting it behind a build flag to avoid forcing all nomad users to
install liblxc (lxc-dev for development).
