[Python] TypeError: __init__() got an unexpected keyword argument 'encode_multipart'

Description

When calling a DELETE API that has consumes = "application/x-www-form-urlencoded", I get the error in the subject.

Swagger-codegen version

2.3.1

Swagger declaration file content or url

...
			"delete": {
				"consumes": [
					"application/x-www-form-urlencoded"
				],
				"produces": [
					"application/json"
				],
				"responses": {
					"200": {
						"description": "successful response",
						"schema": {
							"$ref": "#/definitions/MyResponse"
						}
					}
				},
				"parameters": [
					{
						"description": "User identifier",
						"required": true,
						"type": "string",
						"name": "user",
						"in": "path"
					},
					{
						"description": "List of file names to delete",
						"items": {
							"type": "string"
						},
						"required": true,
						"collectionFormat": "csv",
						"in": "path",
						"type": "array",
						"name": "fileNames"
					}
				],
				"description": "Deletes files for a user",
				"summary": "Delete Files",
				"operationId": "deleteFiles"
			}

Command line used for generation

swagger-codegen generate -i "https://my-url" -l python -o "/my-path" -DpackageName=my_project -DprojectName=my-project

using python 2.7.10, with urllib3 1.22, on Mac OS 10.13.

Steps to reproduce

My code calls something like user_api.delete_files('johndoe', ['foo']). It prints this error:

Traceback (most recent call last):
  File "examples.py", line 41, in <module>
    user_api.delete_files('johndoe', ['foo'])
  File "build/bdist.macosx-10.13-intel/egg/my_project/api/user_api.py", line 1245, in delete_tags
  File "build/bdist.macosx-10.13-intel/egg/my_project/api/user_api.py", line 1331, in delete_tags_with_http_info
  File "build/bdist.macosx-10.13-intel/egg/my_project/api_client.py", line 322, in call_api
  File "build/bdist.macosx-10.13-intel/egg/my_project/api_client.py", line 153, in __call_api
  File "build/bdist.macosx-10.13-intel/egg/my_project/api_client.py", line 388, in request
  File "build/bdist.macosx-10.13-intel/egg/my_project/rest.py", line 265, in DELETE
  File "build/bdist.macosx-10.13-intel/egg/my_project/rest.py", line 175, in request
  File "/Library/Python/2.7/site-packages/urllib3/request.py", line 66, in request
    **urlopen_kw)
  File "/Library/Python/2.7/site-packages/urllib3/request.py", line 87, in request_encode_url
    return self.urlopen(method, url, **extra_kw)
  File "/Library/Python/2.7/site-packages/urllib3/poolmanager.py", line 321, in urlopen
    response = conn.urlopen(method, u.request_uri, **kw)
  File "/Library/Python/2.7/site-packages/urllib3/connectionpool.py", line 617, in urlopen
    **response_kw)
  File "/Library/Python/2.7/site-packages/urllib3/response.py", line 467, in from_httplib
    **response_kw)
TypeError: __init__() got an unexpected keyword argument 'encode_multipart'

Related issues/PRs

N/A

Suggest a fix/enhancement

N/A

Start with the generated rest.py DELETE/request path and api_client.py call_api shown in the traceback, then compare how a DELETE operation with application/x-www-form-urlencoded is passed to urllib3. Reproduce the failure with the supplied delete_files example and verify that the generated client completes the request without the encode_multipart TypeError.