Floris

This release of FLORIS includes the following new features and updates:

- Improved logging infrastructure for console logging and file logging
- Expanded examples
- Support for Python 3.6
- Updates to GCH vortex calculation and effective yaw
- Improved tuning
- Added infrastructure for pre-commit hooks and consistent source code linting

This bug fix release corrects an issue plotting cut-through planes where nans occured on boundary of plane

A bug was identified where a turbine's turbulence intensity (TI) was retained even after reinitializing the flow field. Code was changed to correctly reset the TI using the reinitialize_turbines() method.

This was described fully in pull request
https://github.com/NREL/floris/pull/16

Update power loss in yaw for above rated according to method in Optimising yaw control at wind farm level by Ervin Bossanyi