handle --form more correctly (#385)

test/fixtures/curl_commands/get_with_form.sh

@@ -1,6 +1,6 @@
 curl -s --user 'test' \
   http://localhost:28139/v3 \
   -F from='test@tester.com' \
-  -F to='devs@tester.net' \
+  --form-string to='devs@tester.net' \
   -F subject='Hello' \
   -F text='Testing the converter!'

test/fixtures/python/multipart_post.py

@@ -6,7 +6,7 @@ headers = {
 
 files = {
     'attributes': (None, '{"name":"tigers.jpeg", "parent":{"id":"11446498"}}'),
-    'file': ('myfile.jpg', open('myfile.jpg', 'rb')),
+    'file': open('myfile.jpg', 'rb'),
 }
 
 response = requests.post('https://localhost:28139/api/2.0/files/content', headers=headers, files=files)

test/fixtures/python/post_image.py

@@ -1,7 +1,7 @@
 import requests
 
 files = {
-    'image': ('image.jpg', open('image.jpg', 'rb')),
+    'image': open('image.jpg', 'rb'),
 }
 
 response = requests.post('http://localhost:28139/targetservice', files=files)

test/fixtures/python/post_with_extra_whitespace.py

@@ -7,7 +7,7 @@ headers = {
 }
 
 files = {
-    'files': ('47.htz', open('47.htz', 'rb')),
+    'files': open('47.htz', 'rb'),
     'name': (None, '47'),
     'oldMediaId': (None, '47'),
     'updateInLayouts': (None, '1'),