Change CI to GitHub actions

Use copier template from oca/oca-addons-repo-template

Target Python3.8

Apply linting

Fix a missing call to super

.prettierrc.yml

@@ -0,0 +1,8 @@
+# Defaults for all prettier-supported languages.
+# Prettier will complete this with settings from .editorconfig file.
+bracketSpacing: false
+printWidth: 88
+proseWrap: always
+semi: true
+trailingComma: "es5"
+xmlWhitespaceSensitivity: "strict"