rados/singleton: make cache mode cycling include readforward mode

 forward -> off -> writeback -> readforward -> ...

Signed-off-by: Sage Weil <sage@redhat.com>
Merge pull request #75 from ceph/wip-readforward

include readforward cache mode in cache mode cycling test

Reviewed-by: Samuel Just <sam.just@inktank.com>
Removed upgrade/dumpling from master branch as it should be only in dumpling branch

Signed-off-by: Yuri Weinstein <yuri.weinstein@inktank.com>
Import teuthology tasks (master branch)

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Merge branch 'teuth_master' into tasks_master
Update module references

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>