Problem with access token while creating Facebook Test Users

I'm trying to create test users for my Facebook application. They announced this functionality in this blog post in November (http://developers.facebook.com/blog/post/429) and it is documented here (http://developers.facebook.com/docs/test_users/). I could not find the answer to this elsewhere...

According to the documentation, "You can create a test user associated with a particular application using the Graph API with the application access token." This links to the section "Autenticating as an Application" and describes this CURL script:

curl -F grant_type=client_credentials \
 -F client_id=your_app_id \
 -F client_secret=your_app_secret \
 https://graph.facebook.com/oauth/access_token

So far, so good. I ran this and get the fo开发者_JS百科llowing:

access_token=1182...18|nTI...r5Q

So now I want to POST this token to the graph api test user URL:

POST /1182...18/accounts/test-users?installed=true&permissions=read_stream&access_token=1182...18|nTI...r5Q  

When I do this (both using the Facebook PHP SDK and just typing it into the browser) I get:

{
    "error": {
      "type": "OAuthException",
      "message": "Invalid OAuth access token."
    }
}

So the questions are:

# Get the access token
resp = requests.get(
    'https://graph.facebook.com/oauth/access_token?grant_type=client_credentials&client_id={app_id}&client_secret={app_secret}'.format(
        app_id=APP_ID, # Your app id (found in admin console)
        app_secret=APP_SECRET  # Your app secret (found in admin console)
    )
)
# Parse the token
token = resp.content.split('=')[-1]

# Create the user
data = {'access_token': str(token)}
resp = requests.post(
    'https://graph.facebook.com/{app_id}/accounts/test-users?installed=true'.format(
        app_id=APP_ID
    ),
    data=data
)
print resp.content