Added feature to make sure kbox create won't overwrite an existing app.
Added feature to make sure kbox create won't overwrite an existing app.

kalabox/kalabox-cli,rabellamy/kalabox,kalabox/kalabox-cli,oneorangecat/kalabox,oneorangecat/kalabox,ManatiCR/kalabox,RobLoach/kalabox,ManatiCR/kalabox,ari-gold/kalabox,ari-gold/kalabox,rabellamy/kalabox,RobLoach/kalabox