Fixed more in README.md
Fixed more in README.md

SheffieldML/forkedGPmat,SheffieldML/forkedGPmat,SheffieldML/forkedGPmat,SheffieldML/forkedGPmat,lawrennd/GPmat,lawrennd/GPmat,lawrennd/GPmat,SheffieldML/forkedGPmat,SheffieldML/forkedGPmat