Auto merge of #79 - pcwalton:downgrade-core-graphics, r=frewsxcv
Auto merge of #79 - pcwalton:downgrade-core-graphics, r=frewsxcv

Downgrade our `core-graphics-rs` version so that we don't pull in serde 0.7.

Servo isn't ready for that upgrade yet.

r? @metajack (or whoever)

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servo/glutin