bump up version to v0.4.0 #107

	name: ci

	on: [push]

	jobs:
	test:
	name: test
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- uses: actions/cache@v2
	with:
	path: \|
	~/.cargo/registry
	~/.cargo/git
	target
	key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
	- uses: actions-rs/toolchain@v1
	with:
	toolchain: stable
	components: rustfmt, clippy
	- uses: actions-rs/cargo@v1
	with:
	command: fmt
	args: --all -- --check
	- uses: actions-rs/cargo@v1
	with:
	command: clippy
	- uses: actions-rs/cargo@v1
	with:
	command: test
	args: -- --nocapture --format pretty
	- uses: actions-rs/cargo@v1
	with:
	command: build
	args: --examples
	- uses: actions-rs/cargo@v1
	with:
	command: build
	args: --bins

Provide feedback