Auto merge of #13190 - servo:cssparser-up, r=Manishearth

Update cssparser

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tests/unit/style/Cargo.toml

@@ -11,7 +11,7 @@ doctest = false
 
 [dependencies]
 app_units = "0.3"
-cssparser = {version = "0.6", features = ["heap_size"]}
+cssparser = {version = "0.7", features = ["heap_size"]}
 euclid = "0.10.1"
 rustc-serialize = "0.3"
 selectors = {version = "0.13", features = ["heap_size"]}