Containerize XOS API sanity tests

Create a container image containing the cord-tester source.  The goal is to be able to run XOS API tests on XOS deployed on Kubernetes by launching a testing pod.  A sample invocation might look like the following:

kubectl run -i --tty --image xosproject/xos-api-tester api-tester --restart=Never --rm -- Ch_ServiceTest.txt Ch_UserTest.txt

The invocation above would download the xos-api-tester container from Docker Hub, run the service and user tests, and output the results to the shell.

Google doc that goes into more detail:

https://docs.google.com/document/d/1ztSoaim1K00O6GfqZhTlnbZlX9hA5hpS2N6ssSEkRW4/edit?usp=sharing