Bump Maven driven build to java 7
Bump Maven driven build to java 7

Change-Id: I90a2883c0f39b19fbc94098dfbbdc3bd4b22f110

GerritCodeReview/plugins_cookbook-plugin,akilman/appd-hackathon-2016,akilman/appd-hackathon-2016,GerritCodeReview/plugins_cookbook-plugin,pgroudas/gerrit-keep-approvals,akilman/appd-hackathon-2016,GerritCodeReview/plugins_cookbook-plugin,pgroudas/gerrit-keep-approvals