v1.0.0 -- Permissions, SelectMenus, New Option Types

This PR adds several new features:

• Additional option types NUMBER and MENTIONABLE (#38, thank you @williamhatcher!)
• Command permissions (#21, #40)
• The SelectMenu component (#37, #39)

This is version 1.0.0. This means that this library is committing to maintaining a stable API going forward, in order to support the numerous projects that have begun using it.

How do I know when to release 1.0.0?
If your software is being used in production, it should probably already be 1.0.0. If you have a stable API on which users have come to depend, you should be 1.0.0. If you’re worrying a lot about backwards compatibility, you should probably already be 1.0.0.
- SemVer FAQ