Allow plugin to run under Craft 5

[julianschelker]

The plugin seems to work just fine with Craft 5 in one of our applications.

Currently we have it installed as File with the following changes in our project composer.json:

"repositories": [
  ...
  {
      "type": "package",
      "package": {
        "name": "codemonauts/craft-readonly-field",
        "version": "2.1.0",
        "dist": {
          "url": "/opt/libraries/php/codemonauts-craft-readonly-field-2.1.0.tar",
          "type": "tar"
        },
        "type": "craft-plugin",
        "autoload": {
          "psr-4": {
            "codemonauts\\readonly\\": "src/"
          }
        },
        "extra": {
          "name": "Read-only Field",
          "handle": "readonly",
          "class": "codemonauts\\readonly\\ReadonlyPlugin"
        }
      }
    },
]

To allow php to find it we store the archived plugin in artifacts folder and map it into our docker container. docker-compose.yml:

   ...
    volumes:
      - ./artifacts:/opt/libraries/php