Added a test runner that launches tests on AWS

refs #6429 

It will automatically launch an instance on AWS (or reuse an already running) and execute the tests there. It takes about 17 seconds to execute Unit tests and 3 minutes to execute Integration tests. Forgot how long system tests take. Maybe 15 minutes.

UI tests are still "slow". It takes about 30 minutes. 

In general we can do much more here but I wanted to keep it simple for a first version. For instance we can implement a much smarter version of reusing a running instance, we could maybe run multiple tests in parallel to reduce execution time further etc. We currently use `c3.large` instances and they are basically bored... Maybe 20-25% CPU usage and network/disk is not much used either.