app-rm: remove app if it failed
app-rm: remove app if it failed

Currently if a sandbox app failed, it cannot be removed because it is
assumed to be still running. This fixes it.

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