Add Develocity to a the membership.eclipse.org Webdev repository build

After the Develocity demo, I'd like to look at adding Develocity to some of our longer builds, starting with the membership.eclipse.org repository. The builds are typically 10m-15m long, with the Java portion of the build having ~400 tests and taking 6m on average, so they aren't as long as some of the other consumers, but they should see a decent improvement and could help us evaluate the kind of savings we could see in other internal projects.