Update all user-journeys mockups to use blockstack

[satazor]

All the mockups should use blockstack for the identity/authentication part.

[satazor]

When #3 is done, we should schedule a meeting with @diasdavid to decide if we go with the extension or the website.

[daviddias]

[daviddias]

The extension will enable users to quickly "discussify" links, but it will require a nice webpage to have a view of all the comments, otherwise it will be all cramped in an extension box.

[satazor]

@diasdavid The extension will have an option to expand into a larger view. For now, due to time constraints to develop the POC, we must opt for either the website or the extension. Later on, a lot of code can be reused in both codebases.

[ghost]

This issue was already solved here: #12