title: Bitbucket API returns 'Bad request' when using python requests
body: <p>I want to make a request to Bitbucket API to create repository.
  The following curl works:</p>
  
  <pre><code>curl -v -X POST -d '{"scm": "git", "is_private": "true", "fork_policy": "no_forks", "project": {"key": "MARS"}}' -H "Content-Type: application/json"  https://api.bitbucket.org/2.0/repositories/myteam/test -u &lt;user-name&gt;
  </code></pre>
  
  <p>So I tried the same in python using requests:</p>
  
  <pre><code>data = {'scm': 'git', 'is_private': 'true', 'fork_policy': 'no_forks', 'project': {'key': 'MARS'}}
  auth=(user, password)
  headers = {"Content-Type": "application/json"}
  url = "https://api.bitbucket.org/2.0/repositories/myteam/test"
  res = requests.post(url, data=data, headers=headers, auth=auth)
  </code></pre>
  
  <p>but the <code>res</code> returns 'Bad request' (400). why?</p>