Publish 1.0-alpha release to Maven Central

[basshelal]

When all is fully tested to be working on all platforms, we should publish a 1.0-alpha release to Maven Central.

This release should include with it the native shared libraries of RtMidi so consumers use bundled libraries, so before we can do that we need to ensure that basshelal/RtMidi-Builds#3 is met, so that we have verified and lean libraries that will be used by consumers of the supported platforms.

The release is alpha because I need to ensure it's usable (and works well) by clients through Maven Central, basically mimicking a real life scenario. This will be done by doing an example project that pulls from Maven Central, see #1

If that works well (which it probably should), then we can go for a full fat 1.0