Allow editing blog details on setup
Allow editing blog details on setup

closes #5526
- when user creates blog we set `blogCreated` flag to true and
  depending on it make `POST` or `PUT` request

acburdine/Ghost-Admin,dbalders/Ghost-Admin,airycanon/Ghost-Admin,airycanon/Ghost-Admin,JohnONolan/Ghost-Admin,dbalders/Ghost-Admin,JohnONolan/Ghost-Admin,TryGhost/Ghost-Admin,kevinansfield/Ghost-Admin,TryGhost/Ghost-Admin,acburdine/Ghost-Admin,kevinansfield/Ghost-Admin