If you are running docker-machine version v0.2 stable, you can’t set docker option in light way. But in next version v0.3 this problem was resolved with the creation parameters.
At this moment this feature it’s on RC1,then you can use a version v0.3.0-RC-1 or wait for delivery the next stable version v0.3.0(tentatively Jun.16).
Then use parameter --engine-insecure-registry to set --allow-insecure-ssl for docker’s daemon, for example:
docker-machine create --driver virtualbox --engine-insecure-registry myregistry:5000 dev
After that you can execute:
docker run myregistry:5000/busybox:latest echo 'hello world'
Additionally you can read about it on project doc.