Merge #346

346: Temporary change pin mode r=therealprof a=burrbull

Code from `stm32l0xx-hal` partially used.

Co-authored-by: Andrey Zgarbul <zgarbul.andrey@gmail.com>

Author: bors[bot]

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- Temporary change pin mode
 - More badges in README
 - `RccBus` & `GetBusFreq` traits. `AHBx`, `APBx` structures.
 - Filler `NoPin` type