SAK-23179 update purepoms parent to 2.8.7

git-svn-id: https://source.sakaiproject.org/svn/common/branches/common-1.1.x@118974 66ffb92e-73f9-0310-93c1-f5514f145a0a
[maven-release-plugin] prepare release common-1.1.8

git-svn-id: https://source.sakaiproject.org/svn/common/branches/common-1.1.x@118978 66ffb92e-73f9-0310-93c1-f5514f145a0a
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://source.sakaiproject.org/svn/common/branches/common-1.1.x@118980 66ffb92e-73f9-0310-93c1-f5514f145a0a