set osm-common to v9.0

Change-Id: I2ecf4ea0ea5502193338834f6ecd4775da529597
Signed-off-by: endika <endika.aldecoa@ehu.eus>
diff --git a/requirements.txt b/requirements.txt
index e8c4db4..ffff9fa 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,7 +12,7 @@
 #     See the License for the specific language governing permissions and
 #     limitations under the License.
 
-git+https://osm.etsi.org/gerrit/osm/common.git#egg=osm-common
+git+https://osm.etsi.org/gerrit/osm/common.git@v9.0#egg=osm-common
 juju==2.8.4
 pyasn1>=0.4.4
 kubernetes==10.0.1