Use Codecov for recording and reporting code coverage information

Author: per1234

Diff for: .github/workflows/test.yml

@@ -64,6 +64,14 @@ jobs:
       - name: Run unit tests
         run: task go:test-unit
 
+      - name: Send unit tests coverage to Codecov
+        if: matrix.operating-system == 'ubuntu-latest'
+        uses: codecov/codecov-action@v1
+        with:
+          file: ./coverage_unit.txt
+          flags: unit
+          fail_ci_if_error: true
+
       - name: Install Python
         uses: actions/setup-python@v2
         with:

Diff for: README.md

@@ -3,6 +3,7 @@
 [![Tests Status](https://github.com/arduino/arduino-lint/workflows/Run%20tests/badge.svg)](https://github.com/arduino/arduino-lint/actions?workflow=Run+tests)
 [![Nightly Status](https://github.com/arduino/arduino-lint/workflows/Nightly%20build/badge.svg)](https://github.com/arduino/arduino-lint/actions?workflow=Nightly+build)
 [![Docs Status](https://github.com/arduino/arduino-lint/workflows/Publish%20documentation/badge.svg)](https://github.com/arduino/arduino-lint/actions?workflow=Publish+documentation)
+[![Codecov](https://codecov.io/gh/arduino/arduino-lint/branch/main/graph/badge.svg?token=nprqPQMbdh)](https://codecov.io/gh/arduino/arduino-lint)
 
 **Arduino Lint** is a command line tool that checks for common problems in [Arduino](https://www.arduino.cc/) projects: