erasure-code: add thrash-erasure-code to suites/rados

Because it needs the thrasher to have min_in: 4 otherewise k=3,m=1 will
block.

http://tracker.ceph.com/issues/9648 Fixes: #9648

Signed-off-by: Loic Dachary <loic-201408@dachary.org>
erasure-code: do not include k=3,m=1 in dumpling-x

Because thrashosd does not have min_in: 4 and that we don't want to set
it because other workloads may be influenced.

Signed-off-by: Loic Dachary <loic-201408@dachary.org>
Merge pull request #162 from dachary/wip-9648-erasure-code-tests

erasure-code: add thrash-erasure-code to suites/rados