Add: Automated config testing

[chrisbliss18]

This PR adds a new script in bin/run-test.php. It takes a variety of parameters in order to run Jetmon repeatedly with different configs in order to test the performance and stability of different configs.

This is a proof-of-concept and needs some additional refinement.

This PR includes a directory (bin/example-test-configs) with a set of test configs. You can run through these configs by running the following from the bin directory:

jetmon/bin$ php run-test.php --run-time=300 --configs-dir=example-test-configs

This will run through each of the configs with each config being run for five minutes. If you need to run docker via sudo, you should be prompted to rerun the script with sudo.

The script supports the -h argument to get more help, such as:

jetmon/bin$ php run-test.php -h

Further short-term refinements needed:

1. Add the ability to select the stats information to output.
2. Add the ability to generate averages, maxes, and mins for the values from each round.
3. Add the ability to track resource utilization (CPU, memory) in the stats.
4. Fix the ability to capture SIGINT, et al. signals to ensure that the script ends cleanly and replaces the original config. The existing code to capture these signals is not working correctly.