Version 2.1.0 released

[mairas]

Hey, I've just released SensESP v2.1.0. This time, the big applause goes to Jan Dytrych and his awesome SensESP web UI improvements! The new changes provide a lot easier device configuration and UI status updates. He also has other cool new features in the pipeline!

Other fixes and improvements:

• Config paths are saved as hashed filenames, lifting the accidental 31 character maximum path length limitation
• CurveInterpolator class documentation and usage improvements