PortRangeService is now part of the ServiceProxies which can now be configured through a bootstrap.json file.

The bootstrap.json file can be specified by:
- Defining the RTBKIT_BOOTSTRAP environment variable
- Placing it in the current working directory
- Calling ServiceProxy::bootstrap with the file path

This file can configure all or any of the components of ServiceProxy
and simplifies the initialization of a service by simply making it
completely optional to initialization a ServiceProxy object when
creating a service.