Lots of updates, including tidying up of project resources.
Add a link checker that runs on travis.

Analogous to CodeClub/CodeClubUK-Projects#12.
Refs CodeClub/CodeClubUK-Projects#11.
Merge pull request #7 from andylolz/11-link-checking

Add a link checker that runs on travis.
Formattin'
Because Travis is stupid.
Force travis to build gh-pages & everything

*hopefully* this is right?!
Added Code Club Scratchcards to the download materials for projects that reference them
Unicode issues with these polish resource zips