[maven-release-plugin] prepare release assignment-2.9.1

git-svn-id: https://source.sakaiproject.org/svn/assignment/branches/assignment-2.9.x@119754 66ffb92e-73f9-0310-93c1-f5514f145a0a
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://source.sakaiproject.org/svn/assignment/branches/assignment-2.9.x@119756 66ffb92e-73f9-0310-93c1-f5514f145a0a
Jenkins post-build: Auto-updating master version to 2.9-SNAPSHOT for next release http://builds.sakaiproject.org:8080/job/assignment%202.9.x/

git-svn-id: https://source.sakaiproject.org/svn/assignment/branches/assignment-2.9.x@119757 66ffb92e-73f9-0310-93c1-f5514f145a0a