Update README.md

Add in david just for kicks.

Change header depth
Update README.md

Set a link to the report on david
Update README.md

Try a bigger whitespace
Try using express `3.*`

Applies to #321 and the beginnings of #249

Lightly related to #262
Merge pull request #322 from Martii/tryExpress3all

Try using express `3.*`

Auto-merging... hopefully deployed later today.
Update README.md

Denote current HEAD is using 3.* for express now... deployment hopefully later today.
Use major releases for current package.json.

* This entails more checking to see if site compatibility busts e.g. if GH changes their OAuth then our site breaks with logins. Conversely our site won't break entirely if the package is updated beyond compatibility. Seems like an even tradeoff to me but we'll give it a try.
* Change README.md to match
* Clean up the headers a bit in README.md

Closes to #321

May affect a portion of #315
Add a missing CDN to README.md
Merge pull request #323 from Martii/useMajor

Use major