Refactor code - then do proper testing

The big lesson in 'refactoring code and relying on unit tests' is a bad idea.

A massive difference where the temperature of fermentation was swinging with 1-1.5degC differential. It turned out the fridge wasn't switching off when the temperature reach the target - instead it was relying on a fall-back protection which turns of the fridge after it has been running for 15 minutes - meaning excessive cooling. 

Setting 1 FLAG gets the difference back to the +/- 0.3 deg intended.

https://github.com/allena29/brewerslab/compare/34fa1a4ff7f78b40bfab95fb2a7b52e1625d45f3...a4c9c946e67b77fca4a9cfb75ad4c7ba9920d99a