Auto merge of servo#242 - nox:heapsize, r=Ms2ger

Allow heapsize 0.3

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Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 
 name = "js"
-version = "0.1.1"
+version = "0.1.2"
 authors = ["The Servo Project Developers"]
 
 build = "build.rs"
@@ -16,5 +16,5 @@ git = "https://github.com/servo/mozjs"
 libc = "0.2"
 rustc-serialize = "0.3"
 log = "0.3"
-heapsize = "0.2"
+heapsize = ">=0.2, <0.4"
 num = "0.1.24"