Fix flexbox usage in IE10/11

- Make sure card .content has flex basis
- Consolidate flex grow/shrink/basis on .column class
- Only override flex-basis on width classes
- Use max-width on width classes to prevent IE10/11 bug with border-box
sizing
(Found while working on issue #5 and issue #6)
Fix author object for sample news post
Post re: sample news posts and listing