Add tests for DateTime type #507

	name: Default CI
	on: [push, pull_request, workflow_dispatch]
	jobs:
	# This workflow contains a job called "test", which is run on every push
	test:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout code
	uses: actions/checkout@v3
	- name: Install Go
	uses: actions/setup-go@v3
	with:
	go-version: ^1.18
	cache: true
	- name: Setup toxiproxy
	run: \|
	wget -O toxiproxy-2.1.4.deb https://github.com/Shopify/toxiproxy/releases/download/v2.1.4/toxiproxy_2.1.4_amd64.deb
	sudo dpkg -i toxiproxy-2.1.4.deb
	sudo cp ws/toxiproxy.service /lib/systemd/system/
	sudo systemctl start toxiproxy
	- name: Run tests
	run: \|
	go test ./ws ./ocppj -v -covermode=count -coverprofile=coverage.out
	go test -v -covermode=count -coverprofile=ocpp16.out -coverpkg=github.com/lorenzodonini/ocpp-go/ocpp1.6/... github.com/lorenzodonini/ocpp-go/ocpp1.6_test
	go test -v -covermode=count -coverprofile=ocpp201.out -coverpkg=github.com/lorenzodonini/ocpp-go/ocpp2.0.1/... github.com/lorenzodonini/ocpp-go/ocpp2.0.1_test
	sed '1d;$d' ocpp16.out >> coverage.out
	sed '1d;$d' ocpp201.out >> coverage.out
	- name: Install goveralls
	run: go install github.com/mattn/goveralls@latest
	- name: Publish coverage
	env:
	COVERALLS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	run: goveralls -coverprofile=coverage.out -service=github

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