nycflights13 1.0.0

• weather$time_hour and flights$time_hour are now stored in the
  America/New_York timezone (#19).

• weather data updated from latest Iowa State mesonet (@rmcd1024, #24).
  wind_gust is now correctly captured from the underlying data, rather than
  being a copy of wind_speed. precip is better captures the hourly
  preciptation (which tends to be recorded at 51 minutes past the hour) (#27)