Remove hanging brackets that cause error, simplify checkSquare function

[AustinMallar]

• Hanging brackets on the last line of app.js causes an error, simply removed to correct.
• Simplify the checkSquare function by removing the "square" parameter as it isn't used in the function.

[thulin82]

• Hanging bracket-fix already existing in Fixed hanging }). #3
• Also, your commits do A LOT more than you are stating, and could be summarized by:
  • Changing ' to "
  • Adding semicolons
  • Expanding IF-syntaxes at line 46-55