fix(deps): pin/upgrade eslint dependencies, fix some errors

[jimmyandrade]

Summary

Proposed changes

This PR brings the following changes:

• Prevent ESLint errors on src/standalone.js;
• Prevent ESLint errors on src/cli.js;
• Upgrade the following dependencies:

{
  "dependencies": {
    "babel-eslint": "10.1.0",
    "eslint": "7.10.0",
    "eslint-plugin-ava": "11.0.0",
    "eslint-plugin-html": "6.1.0",
    "eslint-plugin-import": "2.22.1",
    "eslint-plugin-itgalaxy": "128.0.0",
    "eslint-plugin-jest": "24.0.2",
    "eslint-plugin-jsx-a11y": "6.3.1",
    "eslint-plugin-markdown": "1.0.2",
    "eslint-plugin-node": "11.1.0",
    "eslint-plugin-promise": "4.2.1",
    "eslint-plugin-react": "7.21.2",
    "eslint-plugin-unicorn": "21.0.0"
  }
}

---

Testing

• I have added or updated tests that prove my fix is effective or that my feature works.

How to test

Describe the tests that you ran to verify your changes:

1. git checkout this branch;
2. Run npm test.

Test configuration

• Node.js version: v12.17.0;
• NPM version: v6.14.4.

---

Checklist

• I have added corresponding labels to this PR (like bug, enhancement...);
• My commits follow the Conventional Commits 1.0 Guidelines;
• My code follows the style guidelines of this project;
• I have performed a self-review of my own code;
• I have mapped technical debts found on my changes. They are commented with // eslint-disable-next-line;
• I have made corresponding changes to the documentation (if applicable);
• My changes generate no new warnings or errors;

[jimmyandrade]

LGTM (self-review)