Release 2.0.0.rc1

Breaking changes and move to v2.0.0

Specifically:
- execution profiles are now templates to avoid repeating boilerplate when we want to just use a different a docker image
- Fleshed out type definition support. Better syntax for defining
types and now are checked whenever outputs are generated.
Any types which are missing a required property cause rule
execution to fail.
- fixed support for overriding config variables from command line