Specs and fixes

- Add more specs and better test support
- Updated Versionfile, README and add LICENSE
- Let Travis run all branches
- Add missing locale keys + add Swedish locale
- Use find_by_slug not permalink for Product
- Fixed additional deprecated finders
- RelationType ’name’ and ‘applies_to’ should be required and ’name’
should be unique
- Use new .add_routes instead of .draw
- Minor layout tweaks and new std hooks
fixed deprecated find syntax in related_product_discount.rb

Fixes #80