Scrum index page

This incorporates pull request #429:
* created new page for scrums listing scrums/index
* created a timeline for scrums
* added gem youtube_it
* added gem VCR
Better to create a constant in initializer in its own namespace, eg
```
module Youtube
  YOUTUBE_KEY = ENV['YOUTUBE_KEY']
end
```
and the use it elsewhere as Youtube::YOUTUBE_KEY