Update nanoc gem to latest version
Update rdiscount
Update to latest gem versions
Merge branch 'update-nanoc' into develop
Merge branch 'develop' into fix/html
Move lightbox js to separate script
Escape ampersands in youtube urls
All image functions require alt text
Rake task to validate html
Merge branch 'fix/html' into develop
Add 'what's the point of publishing?'

Signed-off-by: Michael Barton <mail@michaelbarton.me.uk>
Merge branch 'develop'