Update to Assert 2.0

This updates to using Assert 2 and removes the deprecated rake
logic. This is to stay up-to-date with Assert for testing.
Add logging for clients

This updates AndSon so that it will log the requests it makes.
A logger can be set using the chainable calls, otherwise, nothing
is logged. This is to provide some output when services are
called, to help with debugging and analyzing.

Closes #17
Merge pull request #18 from redding/jcr-logging

Add logging for clients