Provides low-, and mid-level properties and matchers for examining rules on aws_security_group.
* Second draft of docs for SG rules interface; need to clarify semantics of reject
* First cut at unit tests
* Cleanup test fixtures
* Implementation for allow, with plausible unit tests
* Doc updates based on reality
* Add integration tests; move allow to allow_ / out; several docs updates
* Add be_open_to_the_world and be_open_to_the_world_on_port
* Update docs to reflect adding allow_only
* Update docs to reflect use of position to allow multiple rules with 'only'
* Implement allow_only with unit tests; still need integration tests
* Add integration tests for allow_only
Signed-off-by: Clinton Wolfe <clintoncwolfe@gmail.com>
