Publish snapshot builds

[nlisker]

Testing fixes after they are implemented but before the release helps verify the fixes in time. It's also a much easier alternative than requiring the user to locally build the project. There was prior discussion on this in #773 (comment).

[rhusar]

To summarize the chat, @jamezp any objections if I enable SNAPSHOTS on Central? https://central.sonatype.org/publish/publish-portal-snapshots/

[nlisker]

Has there been more discussion here? I'd like to test the fix for #773 and the upcoming fixes for #771 and #772. The latter might incur breaking changes, so it's best to test them in a snapshot build.

[jamezp]

@rhusar It seems fine to enable SNAPSHOT's to me.