Add support to change database being used based on request parameter.

The diff of the test file makes it look like I changed the whole thing.  I really just wrapped the main tests in a function so that they could be called with both configuration options.  

**Updates**
Extend configuration options to allow a request parameter to set which
database is being used for each action.
Update tests to support both configuration options.
Remove agent configuration for request so that it will not override
application level configurations for nano.