Don't support tmpfs in API version < 1.22

Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>

docker/utils/utils.py

@@ -781,6 +781,8 @@ def create_host_config(binds=None, port_bindings=None, lxc_conf=None,
         host_config['CpuPeriod'] = cpu_period
 
     if tmpfs:
+        if version_lt(version, '1.22'):
+            raise host_config_version_error('tmpfs', '1.22')
         host_config["Tmpfs"] = convert_tmpfs_mounts(tmpfs)
 
     return host_config

tests/unit/container_test.py

@@ -1016,6 +1016,7 @@ class CreateContainerTest(DockerClientTest):
                                }
                              }}'''))
 
+    @requires_api_version('1.22')
     def test_create_container_with_tmpfs_list(self):
 
         self.client.create_container(
@@ -1044,6 +1045,7 @@ class CreateContainerTest(DockerClientTest):
             DEFAULT_TIMEOUT_SECONDS
         )
 
+    @requires_api_version('1.22')
     def test_create_container_with_tmpfs_dict(self):
 
         self.client.create_container(