Update Fedora to use current release
Update Fedora to use current release

 - dnf replaces yum (avoiding warning message)
 - only the docker package needs to be installed
 - 'dnf clean all' after package installation

pcarranzav/resin-aerofs,jpetazzo/dind,cviebig/docker-arch-docker,pekermert/dind,stevenzeiler/dind,resin-io-projects/resin-aerofs,pombredanne/dind,karlkfi/dind