WIP add consumer code to lapine

- TBD how does consumer/Rails code get required?
Add ruby-usdt
WIP fixes to consumer

- loads Rails environment if present
- fix namespace when loading files
- only log some statements when --debug
- WIP actual integration test in runner_spec fails
yaml_config on config is private
Dispatcher fires *return* dtrace probe on method exit
Fix runner_spec to use correct topology
0.2.0