Add --amazonec2-block-duration-minutes flag (#3796)
Add --amazonec2-block-duration-minutes flag (#3796)

* Add --amazonec2-block-duration-minutes flag

Signed-off-by: Ondrej Cifka <2732789bb6a01d700b111613051129629db60901@cifka.com>
Signed-off-by: Nathan LeClaire <38947c4d2b13dfd9789405506441b98609e8975e@gmail.com>

voutilad/machine,docker/machine,dweomer/docker-machine,exoscale/docker-machine,londoncalling/machine,docker/machine,SvenDowideit/machine,dgageot/machine,dgageot/machine,dweomer/docker-machine,ibuildthecloud/machine,exoscale/docker-machine,larsla/machine,flavio/machine,flavio/machine,ibuildthecloud/machine,Herbis/machine,SvenDowideit/machine,londoncalling/machine,voutilad/machine,larsla/machine,Herbis/machine