Changed TenacityBundle to be a ConfiguredBundle. This allowed for several things:
- reduce the boiler plate for integrating with tenacity, common code is now part of the bundle and the client only needs to supply application specific stuff
- allow for PropertyKeys to be configured based of a configuration file
Update README.md

Added new instructions for integrating tenacity after the change.
fixed a bug where we were simply creating a Register but not calling register() on it, which made it a no-op
Merge branch 'configured_bundle' of github.com:velocipedist/tenacity into configured_bundle
fixed spelling
Merge pull request #10 from velocipedist/configured_bundle

Changed the TenacityBundle to be a configured bundle. Now instead of registering the `TenacityPropertyKey` instances and `TenacityPropertyKeyFactory` instance at bundle creation time this is done during the execution of the dropwizard `run` method. This means that the user has access to the configuration file while creating the property keys. Additionally, this allowed for automation of the registering process.