Remove horizon session db.

 * Removes stale sessions
 * Forcefully logs out the user between runs

Change-Id: I5374076283b8bc63826004c455b86afc86009b00
diff --git a/stack.sh b/stack.sh
index 1dadb23..86764f0 100755
--- a/stack.sh
+++ b/stack.sh
@@ -749,6 +749,8 @@
     rm -fr ${HORIZON_DIR}/openstack-dashboard/quantum
     ln -s ${QUANTUM_CLIENT_DIR}/quantum ${HORIZON_DIR}/openstack-dashboard/quantum
 
+    # Remove stale session database.
+    rm -f $HORIZON_DIR/openstack-dashboard/local/dashboard_openstack.sqlite3
 
     # ``local_settings.py`` is used to override horizon default settings.
     local_settings=$HORIZON_DIR/openstack-dashboard/local/local_settings.py