Matching a query param with no value

Investigate the disabled test in ErsatzRequestTest queryWithNoValue to see what is going on there...

There needs to be a way to test whether or not a query of a given name exists (with any or no value)
There needs to be a way to test whether or not a query of a given name matches a value
re work the forward-facing matchers to be specific to the API rather than hamcrest so that they can be more explicit to what they are doing

cjstehno / ersatz