I added a Jenkins job to build PRs as they come in. The Jenkins job is
here  and you can see an example of a failing PR build here . I'll
close the failing PR in the next couple of days.
Right now, Jenkins builds the optional profile and runs the junit tests
(but skips the integration tests). If anyone wants me to reconfigure the
build or has additional advice, let me know.
Jenkins will build a PR when it is opened and when addition commits are
added to the PR.
By the way, Accumulo has a special profile ("Sunny") that runs a subset of
their tests ("Sunny Day Tests") when a PR comes in. It looks like they use
annotations to mark which tests fall into this category . Very cool!