Build prerequisites

rust with wasm32-unknown-emscripten target - instruction to setup can be found here
make sure emcc tool is in the PATH since build script uses it internally
wasm build util, run cargo install --git https://github.com/paritytech/wasm-utils wasm-build to install
bash to run ./build.sh

Build

./build.sh

cargo test --manifest-path="contract/Cargo.toml" --features std