Enable 'std' feature on critical-section for WASM

This fixes the WASM support which was failing due to missing
critical-section implementation. This also upgrades the bindgen
dependency and ensures that tooling works.

examples/wasm/Cargo.toml

@@ -15,4 +15,4 @@ wasm-logger = "0.2.0"
 wasm-bindgen = "0.2"
 web-sys = { version = "0.3", features = ["Document", "Element", "HtmlElement", "Node", "Window" ] }
 log = "0.4.11"
-critical-section = "1.1"
+critical-section = { version = "1.1", features = ["std"] }