Update system tests, move to our latest conventions

This is a minor change that simply updates the system tests to
our latest conventions. This renames the file to match the part
of `AndSon` that we are system testing. This is our latest
convention for defining system tests. This also updates the tests
to our latest standards. Specifically this included renaming the
support `FakeServer` to `TestServer`. This is to avoid confusion
with the word "fake" in a test suite. The `TestServer` is a
`TCPServer` and processes requests. It is not a full featured
`Sanford` server. This is setup for future changes that need to
add or change system tests.
Merge pull request #39 from redding/jcr-redo-system-tests

Update system tests, move to our latest conventions
Allow adding a response for a service for any params

This updates the stored response "stubbing" to allow stubbing only
a service name and having any calls made to that service generate
a response. This is useful in testing for cases where there isn't
any need to generate different responses for different params.
For example, to test how a part of code behaves when a service
returns a failing response you would stub the response to return
a 500 status code. Previously, you had to stub the service with the
params you expected to be called. This is annoying and typically
we just want to say whatever calls this service, return a 500 no
matter what params it receives. This allows for simpler tests that
focus only on the pieces that we care about and don't have extra
cruft that hides the goal of the test.

This makes the interface similar to `Assert`'s stubbing interface
and isn't backwards compatible. All the previous behavior is still
present, only the interface for using it has changed.

This also starts changes to the system tests to match our current
conventions. This moves the stored response system tests to a
client tests file and updates them to test multiple scenarios.