support rw bind mode in docker module

cloud/docker

@@ -358,6 +358,13 @@ class DockerManager:
                 if len(parts) == 2:
                     self.volumes[parts[1]] = {}
                     self.binds[parts[0]] = parts[1]
+                # with bind mode 
+                elif len(parts) == 3:
+                    if parts[2] not in ['ro', 'rw']:
+                      module.fail_json(msg='bind mode needs to either be "ro" or "rw"')
+                    ro = parts[2] == 'ro'
+                    self.volumes[parts[1]] = {}
+                    self.binds[parts[0]] = {'bind': parts[1], 'ro': ro}
                 # docker mount (e.g. /www, mounts a docker volume /www on the container at the same location)
                 else:
                     self.volumes[parts[0]] = {}