Flip/edit images where necessary to keep the light source consistent

[phet-steele]

@arouinfar there is a lot of light source mixing with the item images. All fruit are backwards, and other images scattered here and there backwards. For example:

This:

Should be flipped to this (image from Proportion Playground, it's slightly different):

Keeping in mind that the respective item in each bag should also be flipped.

@arouinfar up to you if you want this done before publication. It would be good for consistency.

[pixelzoom]

If this gets fixed, it needs to be fixed in the .ai files, not in the .png files or (worse) by flipping in the code.

Here's the artwork that has inconsistent lighting, these files live in https://github.com/phetsims/unit-rates/tree/master/assets:

apple.ai apple_bag.ai lemon.ai lemon_bag.ai orange.ai orange_bag.ai pear.ai pear_bag.ai

After the .ai files are modified, I'll need PNG files with the same dimensions that they are now:

apple.png 63x73 apple_bag.png 138x156 lemon.png 65x49 lemon_bag.png 138x156 orange.png 60x54 orange_bag.png 139x157 pear.png 61x83 pear_bag.png 138x157

[arouinfar]

Thanks for the suggestion @phet-steele. I think this is something that @amanda-phet has also brought up at some point. I will update the files in @pixelzoom's comment.

[arouinfar]

Reflected artwork has been emailed to @pixelzoom.

[pixelzoom]

@arouinfar @phet-steele please verify in: http://www.colorado.edu/physics/phet/dev/html/unit-rates/1.0.0-dev.73/unit-rates_en.html

Last one to verify, please close.

[pixelzoom]

@arouinfar noted that the Shopping Lab screen icon also needs to be fixed.

shopping_lab_screen_icon.png, 548x373

[pixelzoom]

Shopping Lab screen icon received from @arouinfar, integrated in above commit.

@arouinfar please verify in: http://www.colorado.edu/physics/phet/dev/html/unit-rates/1.0.0-dev.74/unit-rates_en.html

[arouinfar]

:+1: