Deleted unnecessary whitespaces and tabs, corrected a pair of quotation marks inside the comment for class Cell.
Deleted unnecessary whitespaces and tabs, corrected a pair of quotation marks inside the comment for class Cell.

tetherless-world/ecoop,epifanio/ecoop-1,tetherless-world/ecoop,epifanio/ecoop-1,epifanio/ecoop-1,tetherless-world/ecoop