Remove resource [(#890)](GoogleCloudPlatform/python-docs-samples#890)

* Remove resource fixture

* Remove remote resource

Author: Jon Wayne Parrott

samples/snippets/face_detection/faces_test.py

@@ -17,10 +17,12 @@
 
 from faces import main
 
+RESOURCES = os.path.join(os.path.dirname(__file__), 'resources')
 
-def test_main(resource, tmpdir):
+
+def test_main(tmpdir):
     out_file = os.path.join(tmpdir.dirname, 'face-output.jpg')
-    in_file = resource('face-input.jpg')
+    in_file = os.path.join(RESOURCES, 'face-input.jpg')
 
     # Make sure there isn't already a green box
     im = Image.open(in_file)