Hi!
CircleCI API v1.1 seems to be setting Content-Type: text/plain; charset=utf-8 in it’s responses. This may lead to undesirable effects as some tools rely on returned Content Type when parsing reponse without ability to force it manually (i.e. Ansible uri module ). I think that setting Content-Type to application/json would make more sense and would make consuming API more straightforward 
Dawid