Update to simd-json 0.7

Author: dtolnay

Cargo.toml

@@ -12,7 +12,7 @@ json = { version = "0.12", optional = true }
 rustc-serialize = { version = "0.3", optional = true }
 serde = { version = "1.0", features = ["derive"], optional = true }
 serde_json = { version = "1.0", optional = true }
-simd-json = { version = "0.6", optional = true}
+simd-json = { version = "0.7", optional = true}
 time = "0.3"
 
 [features]