qa/rgw: verify suite selects a random bucket sharding configuration

Signed-off-by: Casey Bodley <cbodley@redhat.com>

diff --git a/qa/suites/rgw/verify/sharding$ b/qa/suites/rgw/verify/sharding$
new file mode 120000 (symlink)
index 0000000..148393c
--- /dev/null
+++ b/qa/suites/rgw/verify/sharding$
@@ -0,0 +1 @@
+.qa/rgw_bucket_sharding
\ No newline at end of file