Add Emscripten build in Travis

travis.sh

@@ -42,6 +42,22 @@ if [ -n "${CLIPPY}" ]; then
 
     cd "$DIR/test_suite/no_std"
     cargo clippy -- -Dclippy
+elif [ -n "${EMSCRIPTEN}" ]; then
+    CARGO_WEB_RELEASE=$(curl -L -s -H 'Accept: application/json' https://github.com/koute/cargo-web/releases/latest)
+    CARGO_WEB_VERSION=$(echo "${CARGO_WEB_RELEASE}" | sed -e 's/.*"tag_name":"\([^"]*\)".*/\1/')
+    CARGO_WEB_URL="https://github.com/koute/cargo-web/releases/download/${CARGO_WEB_VERSION}/cargo-web-x86_64-unknown-linux-gnu.gz"
+
+    mkdir -p ~/.cargo/bin
+    echo "Downloading cargo-web from: ${CARGO_WEB_URL}"
+    curl -L "${CARGO_WEB_URL}" | gzip -d > ~/.cargo/bin/cargo-web
+    chmod +x ~/.cargo/bin/cargo-web
+
+    # Install Node.js
+    nvm install 9
+
+    cd "$DIR/test_suite"
+    cargo web test --target=asmjs-unknown-emscripten --nodejs
+    cargo web test --target=wasm32-unknown-emscripten --nodejs
 else
     CHANNEL=nightly
     cd "$DIR"