Officially migrate to @cassette packages on npm

[benwiley4000]

We'll wait to do this until v2.0.0 is released officially.

This means:

1. Republish all react-responsive-audio-player releases with the same versions on npm as @cassette/player
2. Mark the react-responsive-audio-player package as deprecated on npm. Note that any future security updates to v1 will be published to the @cassette/player package and that v2 is also available. Note that the fastest way to get rid of the deprecation notice is to switch the package name to @cassette/player and that they can upgrade to v2 later.