[developers] Releasing jars to maven central

Lantern uses a special script and the nexus staging maven plugin to release to central. With ./bin/mvnrelease.bash on your path, you can do the following:

mvnrelease.bash gpg-password git-username git-password

in the same directory that has the pom.xml of the project you want to release. That will automatically supply your usernames and passwords when the various called subroutines require them.

Note that the mvnrelease.bash script also looks for releasePrepare.exp and releasePerform.exp in the same directory. Those files are also found in bin, so one easy approach is to copy all three files to somewhere on your path like /usr/local/bin

To do the above manually, simply run:

mvn release:clean
mvn release:prepare
mvn release:perform
cd target/checkout/ 
mvn nexus-staging:release