Fixed major bug:
-The toString method was not showing that the array could have ending zero's, making the length longer and throwing off the greaterThan, lessThan, and equal methods, which then messed up the add, subtract, and divide.
-To fix this at the end of each method, I changed the return so that it returned a new BigNumber off of a toString, which already eliminates ending zero's
-Also made divide work
Added test for divide and changed Strings for numbers so that they were easier to read and follow along