Load-test with python locust - to test service resilience

[agstephens]

We should do some testing of the production web service to test how it stands up to receiving many requests. These requests should not be data requests, they should poll quick end-points such as:

• GetCapabilities
• DescribeProcess

We could use Locust to do this:

• https://locust.io/

An example of using it for one of our services is here:

• https://github.com/glamod/glamod-wfs-benchmarker