- fix factory.create_blog (it should return blog instance)
- add test create story and create post
- create story test can reproduce the bug that
  stories does not show up on the 'Your Pages' tab in profile page

Repro steps:
1. create a story
2. be redirected to profile page
3. click on 'Your Pages' tag

observed:
- You have not created any pages yet.

expected:
- newly created Story
- !!THIS CHANGE BREAKS THE MIGRATION
- make both Story and Post inherits from Content
- creating a story now show up on Your Pages tab
- fix no such table error when syncdb for the first time
- update blog_sync rq job to also generate stories
- update profile template so that Your Page tab is as pretty as Your Post tab