added a test for problem 4
turned problem four into a function, added some better documentation
changed the order of this logic - improves speed dramatically
typo, fixed
added a note
added a test for problem 5
refactored problem 5, added some better documentation
added problem 6 test
refactored problem 6
typo
added a plot for problem 5
added a test for problem 7
refactored problem 7, named the variables better
hey, this is my first ever Go test! awesome!
implemented problem 1 in Go
minor change to a comment here