v1.50.0

• Add option to set expiration time when creation API tokens

  Examples:

  # Token for 1 hour (3600 seconds)
  particle token create --expires-in 3600
  # Token that never expires (good for cloud applications)
  particle token create --never-expires

• Add particle usb listen as an alias to particle usb start-listening

• Fix particle serial wifi to now time out after 5 seconds if the device is not in USB listening mode.

• Fix spinner to now spin while commands like partilce usb and particle mesh are waiting.