New release 2.1.0

[fsuits]

We are pleased to announce the release of IBM compliance-trestle v2.1.0

In addition to numerous bug fixes and internal enhancements, it includes the following features:

1. ssp-filter can now filter by implementation_status thanks to a contribution by @jpower432
2. ssp's will be internally checked and validated to ensure rule parameter values are unique within a component
3. for developers, most __root__ references have been removed, allowing cleaner code

Enjoy!