Profiles are encoded as base64 zips

They are meant to be transmitted as a single string value,
which is the base64 encoded zip of the profile. They are
not meant to be encoded as a JSON object with a single
'zip' field

Author: shs96c

rb/lib/selenium/webdriver/common/profile_helper.rb

@@ -30,7 +30,7 @@ def self.included(base)
       end
 
       def as_json(*)
-        {'zip' => Zipper.zip(layout_on_disk)}
+        Zipper.zip(layout_on_disk)
       end
 
       def to_json(*)