Extract Nexus URL using nexus-staging-maven-plugin

[vy]

This PR replaces maven-deploy-plugin with nexus-staging-maven-plugin, which allows

• Extracting the resultant Nexus URL during release (i.e., one less manual step in the project release instructions)
• If the build fails half way through, we won’t have anything half deployed

[ppkarwasz]

Great job! 💯

Initially I thought you were parsing the Maven output to find the URL, but you actually found a well-formatted file with the info. 👍