changed the grade input so that it takes a string i.e. A- instead of the number 4.0
added GPA: to the top so students will know what that big number is
Merge pull request #10 from kraftery/bori2

addded the code for class schedule but it doesn't work yet, also worked ...
Merge pull request #11 from kraftery/connor

Connor
validated input that will be entered in the gpa calculator section of the app