Temporarily fix interface tests by shutting the test linode down (#800)

Author: zliang-akamai

tests/integration/linodes/fixtures.py

@@ -325,7 +325,9 @@ def linode_interface_public(linode_cloud_firewall):
 
     wait_until(linode_id=linode_id, timeout=300, status="running")
 
-    # shutdown linode
+    # TODO: add support of creating a offline linode in `create_linode` then remove this workaround
+    exec_test_command(BASE_CMDS["linodes"] + ["shutdown", linode_id])
+
     wait_until(linode_id=linode_id, timeout=60, status="offline")
 
     yield linode_id