Prevent docker containers from running longer than 2 seconds.
Disable access to networking when running code.
Some refractor.
display the cause of a failure for a non-zero exit-code.
Add guards to prevent receiving phoenix related messages.
Explicitly pattern match on shell result.
Merge branch 'timeout_docker' of https://github.com/bjhaid/elixir_experience into bjhaid-timeout_docker

Conflicts:
	web/models/docker.ex
	web/templates/problem/results.html.eex
Merge branch 'bjhaid-timeout_docker'