v0.2.0: Time and webhook parse

Wraps int64 to Time type. New type has a Time() method, that returns time.Time type, casted from original int64 unix timestamp.

The webhook parse function now accepts io.ReadCloser instead of *http.Request. The function originally uses only the body, so this narrowing function parameter is for the greater good.

v0.1.0: Initial version

The version implements public and personal API.