Features
* **when:** add `then_do` API for triggering a callback ([39](https://github.com/mcous/decoy/issues/39)) ([01fb271](https://github.com/mcous/decoy/commit/01fb271)), closes [#31](https://github.com/mcous/decoy/issues/31)
* add `mock` method to replace `create_decoy`, `create_decoy_func` ([37](https://github.com/mcous/decoy/issues/37)) ([d3e0ae9](https://github.com/mcous/decoy/commit/d3e0ae9))
* **spy:** add `inspect.signature` and `repr` support ([35](https://github.com/mcous/decoy/issues/35)) ([0b12237](https://github.com/mcous/decoy/commit/0b12237)), closes [#29](https://github.com/mcous/decoy/issues/29) [#30](https://github.com/mcous/decoy/issues/30)
* **warnings:** add RedundantVerifyWarning ([36](https://github.com/mcous/decoy/issues/36)) ([633159f](https://github.com/mcous/decoy/commit/633159f)), closes [#34](https://github.com/mcous/decoy/issues/34)