Fixed the "untitled" link_node in the walkthrough. Now it reads "Contributers".
Discovered and fixed a bug whereby the demo link would not disappear if a user seeked to a previous part of the video.
Added 4th Learning Lab interactive video.
Adding in a new template for thw WebSockets lab
Merge pull request #128 from rossbruniges/dev

Merging in pull request from @jacobabrennan and adding in a page template to be used in the app
Merge pull request #129 from mozilla/dev

Merging up the WebSockets learning lab from dev to staging
Merge pull request #130 from mozilla/stage

Merging up the WebSockets learning lab from staging to dev