Cleaned up documentation.
Minor changes to Exercise 1 logic. - Changed acceptable grade range from A+ to D- >> A+ to B-, and FZ
Minor changes to Exercise 3 logic. - if statement logic made more streamlined.
Merge remote-tracking branch 'origin/master'

Conflicts:
	exercise1.py
	exercise3.py
Cleaned up documentation.
Minor changes to Exercise 1 logic. - Changed acceptable grade range from A+ to D- >> A+ to B-, and FZ
Minor changes to Exercise 3 logic. - if statement logic made more streamlined.
Cleaned up documentation.
Minor changes to Exercise 1 logic. - Changed acceptable grade range from A+ to D- >> A+ to B-, and FZ
Minor changes to Exercise 3 logic. - if statement logic made more streamlined.
Cleaned documentation. Minor changes to if statement logic. Changed range from A+ to D- and FZ, to A+ to B- and FZ