Centos/RHEL 7 doesn't support tgtd. While the packages are still in
EPEL, there's no point in testing because nobody runs like this.
Switch cinder to use lioadm which uses LIO, and update package
installations.
Depends-On: I964917d13d9415223845ac17eb804ee7faceaf6f
Change-Id: Idc5a4e856bfc93e9dc650d565a98a8e9b3df3481