[manual] API add_subscriptions: Change arguments to support options.

Since in the future we might want requests to add subscriptions to
include things like colors, in_home_view, etc., we're changing the
data format for the add_subscriptions API call to pass each stream as
a dictionary, giving a convenient place to put any added options.

The manual step required here is updating the API version in AFS
available for use with the zephyr_mirror.py system.

(imported from commit 364960cca582a0658f0d334668822045c001b92c)

zephyr/tests.py

@@ -201,7 +201,7 @@ class AuthedTestCase(TestCase):
 
         post_data = {'email': email,
                      'api-key': api_key,
-                     'subscriptions': ujson.dumps(streams),
+                     'subscriptions': ujson.dumps([{"name": stream} for stream in streams]),
                      'invite_only': ujson.dumps(invite_only)}
         post_data.update(extra_post_data)