Publish java11 model packages to Maven Central

[alexellis]

Description

Publish java11 model packages to Maven Central

Given complaints from Java users, we should provide a remote JAR that they can download for the model package, rather than bundling it into their local build.

This enables intelli-sense and removes any "unknown package" errors from IDEs.

I'll close the related issues:

#181
#137

A claim has been put in with Maven Central here using their JIRA ticket system -> https://issues.sonatype.org/browse/OSSRH-59387

[alexellis]

It seems that my previous request may have been approved as it's set to fixed -> https://issues.sonatype.org/browse/OSSRH-48617

[ieugen]

They where published with a different group id and artifact id.
See the comments.

The build + tests and checks could be automated with some CI and also the release process.

[alexellis]

Let's take baby steps, and learn the publishing process (which is very complicated TBH) before running and tripping over our own feet.

https://central.sonatype.org/pages/gradle.html

Latest status: unable to release artifact - https://issues.sonatype.org/browse/OSSRH-59394

[alexellis]

All work completed in #214 and https://github.com/openfaas/templates-sdk