Add additional fractions tests
Adding additional fractions assets
Updating fraction symbol with improved artwork
Running images through ImageOptim
To compress and optimise cross browser
Uppercase versions of 1/y and 1/x to meet syntax needs
Merge pull request #1590 from alphagov/additional_fractions

Additional fraction images

https://www.pivotaltracker.com/story/show/74213934
Adds algebraic and trigonometric fraction images requested by DfE