v8.0.0

• Renamed set() to setValue() for clarity, and to avoid confusion with set() of key-value pair.
• Fixed async mode to have returned types set as Promise or this as appropriate.
• Added private #async to determine the returned methods result.
• Added getValue() method allowing asynchronous operation.

What's Changed

• v8.0.0 by @sciborrudnicki in #12
• v8.0.0 by @sciborrudnicki in #13

Full Changelog: v7.0.0...v8.0.0