Add a Modbus example #49

	name: Go
	on: [push]
	jobs:

	build:
	name: Build
	runs-on: ubuntu-latest
	steps:

	- name: Set up Go 1.20
	uses: actions/setup-go@v1
	with:
	go-version: 1.20
	id: go

	- name: Check out code into the Go module directory
	uses: actions/checkout@v1

	- name: Build
	run: make

	- name: Publish to Registry
	uses: elgohr/Publish-Docker-Github-Action@master
	env:
	SVC: agent
	with:
	name: mainflux/agent
	username: ${{ secrets.DOCKER_USERNAME }}
	password: ${{ secrets.DOCKER_PASSWORD }}
	buildargs: SVC
	dockerfile: docker/Dockerfile

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