Fix get_current_storage_options to work with and without docker
Fix get_current_storage_options to work with and without docker

If we are using docker-storage-setup, user could set DOCKER_STORAGE_OPTIONS
for all other cases it should be STORAGE_OPTIONS.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

Closes: #221
Approved by: rhvgoyal

thescriptbender/container-storage-setup,shishir-a412ed/docker-storage-setup