weathermetrics version 1.2.2

Added new functions to convert wind speed and precipitation:

• convert_wind_speed: Convert a vector of wind speed measurements between common units of wind speed measure (in knots, miles per hour, meters per second, feet per second, and kilometers per hour).
• convert_precip: Convert a vector of precipitation measurements between common units of precipitation measure (in inches, millimeters, and centimeters).
• convert_temperature: Convert a vector of temperature values between common units of temperature measure (in degrees Celsius, Fahrenheit, and Kelvins)