Revert "Remove 'strong_parameters' matcher"

This reverts commit 7e7fb14677fac1e151c93becc3636e7f6731cf51.
Remove dependencies for `StrongParametersMatcher`

Refactor the `StrongParametersMatcher` to work without depending on
bourne for spying on methods. Use an internal spying tool to provide
platform independence.

Other improvements include:

* Standardize `failure_message` method naming
* Properly detect when a matcher does not match
* Add documentation for `permit` matcher.