Generate empty tiles in level editor
Update editor stylesheet

-Define brick dimensions
-Add borders to bricks
-Set top margin for first row
Add color class
Add color to initial bricks in editor
Add style to color palette

-Add <br> tags after sliders
-Format labels
-Convert container to inline-block
Move span.tile rule higher in create.css to match source order in create.html
Refactor onSliderChange method to use Color class in editor.js
Add functionality to onTileClicked even handler
Remove borders from tiles in level editor
Populate bricks array in level object upon editor load
Update x and y properties in Brick class to represent position in pixels