Installer and docker-compose updated to work with Rel SEVEN repo and tags

Change-Id: I914d5517cf3f6e94e4bc96675cf6cb551e10dd0b
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/installers/install_osm.sh b/installers/install_osm.sh
index fcdcdf9..0f5e6bb 100755
--- a/installers/install_osm.sh
+++ b/installers/install_osm.sh
@@ -13,9 +13,9 @@
 #   limitations under the License.
 #
 REPOSITORY_BASE=https://osm-download.etsi.org/repository/osm/debian
-RELEASE=ReleaseSIX
+RELEASE=ReleaseSEVEN
 REPOSITORY=stable
-DOCKER_TAG=6
+DOCKER_TAG=7
 
 function usage(){
     echo -e "usage: $0 [OPTIONS]"