Added ec-readwrite.yaml to the mix to enable erasure code coverage

Signed-off-by: Yuri Weinstein <yuri.weinstein@inktank.com>
Merge pull request #76 from ceph/wip_tune2_upgrade-firefly

Added ec-readwrite.yaml to the mix to enable erasure code coverage

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>