Added Fred as an author
Added a test post by Fred, to check that the functionality works.
Need to:

1. Update _config.yml section on Fred so that the avatar link is to an image of him (rather than Harry Blundun). Also may want to update the spiel
2. Delete the test blog post by him
3. The fred.html should be fine. (All the content is programmatically generated.)
fred.html not successfully added in previous commit because of .gitignore rules about html files. Have added now manually (forcing)
Merge remote-tracking branch 'origin/add-fred-as-author' into posts/js-tracker-0.14.0