kvm: update QEMU version to 2.7.0
kvm: update QEMU version to 2.7.0

ybubnov/rkt,cab105/rkt,coreos/rkt,ybubnov/rkt,coreos/rkt,sstabellini/rkt,lucasallan/rkt,joshix/rkt,sstabellini/rkt,shobhit85/rkt,intelsdi-x/rkt,sstabellini/rkt,joshix/rkt,dgonyeo/rkt,lucasallan/rkt,rkt/rkt,lucasallan/rkt,kinvolk/rkt,jonboulle/rkt,ybubnov/rkt,kinvolk/rkt,cab105/rkt,shobhit85/rkt,lucasallan/rkt,alban/rkt,cab105/rkt,alban/rkt,alban/rkt,intelsdi-x/rkt,joshix/rkt,jakon89/rkt,dgonyeo/rkt,kinvolk/rkt,jakon89/rkt,rkt/rkt,jonboulle/rkt,dgonyeo/rkt,jakon89/rkt,coreos/rkt,intelsdi-x/rkt,Shashwatsh/rkt,achanda/rkt,kinvolk/rkt,Shashwatsh/rkt,jonboulle/rkt,achanda/rkt,achanda/rkt,Shashwatsh/rkt,shobhit85/rkt,joshix/rkt,rkt/rkt,rkt/rkt