Auto merge of #391 - Eijebong:log, r=emilio

Update log to 0.4 and bump version

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Cargo.toml

@@ -2,7 +2,7 @@
 name = "mozjs"
 description = "Rust bindings to the Mozilla SpiderMonkey JavaScript engine."
 repository = "https://github.com/servo/rust-mozjs"
-version = "0.1.11"
+version = "0.1.12"
 authors = ["The Servo Project Developers"]
 build = "build.rs"
 license = "MPL-2.0"
@@ -45,6 +45,6 @@ promises = ['mozjs_sys/promises']
 [dependencies]
 lazy_static = "1"
 libc = "0.2"
-log = "0.3"
+log = "0.4"
 num-traits = "0.1.32"
 mozjs_sys = "0.50.0"