release 0.4.0 "Port of Hamburg"

all implemented features have been tested against a proper SK server
speed after calibration also seems to match with a commercial handheld anemometer

Full Changelog: v0.3.1-beta2...v0.4.0-beta1

initial public release

v0.3.1 is the first version deemed fit for public consumption. all basic features have been implemented, but "real-life" testing was limited to a USB fan and a two-speed hair dryer. use at your own risk, the indicated wind speeds may or may not be off by quite a lot.

Full Changelog: https://github.com/humppafreak/SensESP-PeetBrosWind/commits/v0.3.1-beta2