Wind Speeds default to m/s when units are not provided #139
Description
For example
from metar import Metar
m = Metar.Metar(" KDSM 310507Z COR 34026G45 2SM +TSRA SCT018 BKN023CB BKN041 21/17 A2991 "
"RMK AO2 PK WND 36051/0458 LTG DSNT W-NE RAB06 CONS LTGICCGCC OHD-W-N TS "
"OHD-W-N MOV SE P0000 T02060167")
print(m.wind_gust)
# 45 mpsFMH1 12.6.5 The wind group shall always end with KT to indicate that wind speeds are reported in knots.
The code Datatypes/speed presently defaults to MPS when units are not provided. Perhaps we should default to knots? Thoughts?