compile fix

Course.java wasn't compiling, renamed "marks.size" call on line 22 to
"marks.length" to fix
course changes

added toDel() method, requires you select the Grade you wish to be
deleted
Minor fixes

Fixed formatting, added comments, added MainTest & Manager
Average Calculations

Added methods calculateCurrMark() which calculates the mark based on
grades up to that point, and the calculateOverallMark() which calculates
the overall mark based on all marks within the array. Also added
capability to find a Grade object, given a String corresponding to the
name of the Grade you are looking for.
Update README.md
Overhaul of structure

Changes from delta-nry completed.
Fixed percentage formatting.
Added a testCourse file (will soon update to read the "Grades.txt" file
included) to ensure the course is adding the grades correctly and
calculating the correct mark
Merged from upstream; added changes to Course.java

Separated adding totalScore and myScore in Course.java from its
constructor to a method.