version to 0.9.0

* reorganizations and cleanups to the lib code and test suite #86
* test runner raises custom exception if given an invalid handler class #87
* allow multiple init procs on host configurations #90
* Allow multiple init and run callbacks using callback DSL #91
* test runner now serializes response data #89
* prepend callbacks on service handlers #95
* force string names when defining services on hosts #96
* update to and require the latest sanford-protocol (v0.7.0) (88c56428ab0f159361eba80c281a1804ddecaa15)

/cc @jcredding