Crate covers

The crate stores the implementation of macros

Integration tests are outside in covers_it.

@see https://github.com/dtolnay/proc-macro-hack

Attribute Macros

mock	Marks the following function to be built only for testing purposes
mocked	Wraps the function below for calling another mock function named according to the macro's argument when #[cfg(debug_assertions)] enabled. Call original or mock function according to #[cfg(test)] flag.