Update build workflow to upload JaCoCo code coverage report to codacy.com

[manoelcampos]

In order to make the upload work you need to get a codacy project token.

Getting the coverage badge and codacy project token

• access your project at https://codacy.com, go to "Settings" at the left sidebar
• go to the "General" tab at the top and copy the coverage badge, adding to your README.md.
• go to the "Integrations" tab, open the "Project API" and copy the "Project API Token"

Access your GitHub repository settings tab at the top

• click the "Secrets and variables" at the left side bar, then "actions"
• click the "New repository secret" button and create a variable named CODACY_PROJECT_TOKEN. Its value must the the one copied from the Codacy's "Project API Token" field.