Use context manager while uploading files. (#61)

* use `with open() as ...` to better control context during file uploads.

* remove unused imports.

kiosk_client/job.py

@@ -229,12 +229,11 @@ def upload_file(self):
         headers = self.headers.copy()
         headers['Content-Type'] = ['multipart/form-data']
         name = 'UPLOAD {}'.format(self.filepath)
-        payload = {
-            'file': (self.filepath, open(self.filepath, 'rb'))
-        }
-        response = yield self._retry_post_request_wrapper(host, name,
-                                                          files=payload,
-                                                          headers=headers)
+        with open(self.filepath, 'rb') as f:
+            payload = {'file': (self.filepath, f)}
+            response = yield self._retry_post_request_wrapper(host, name,
+                                                              files=payload,
+                                                              headers=headers)
         uploaded_path = response.get('uploadedName')
         defer.returnValue(uploaded_path)  # "return" the value
 

kiosk_client/manager.py

@@ -28,14 +28,11 @@
 from __future__ import division
 from __future__ import print_function
 
-import io
 import json
 import logging
 import os
-import shutil
 import timeit
 import uuid
-import zipfile
 
 import requests
 from google.cloud import storage as google_storage