feat(config): update all config dependencies, with major updates

BREAKING CHANGE: this updates all configs/plugins this package is based on, as well as supporting ESLint 7. Please refer to the table below:

| package                   | from              | to      |
| ------------------------- | ----------------- | ------- |
| eslint                    | ^5.6.0 and ^6.0.0 | >=5.6.0 |
| eslint-config-airbnb      | 18.0.1            | 18.1.0  |
| eslint-config-prettier    | 6.1.0             | 6.11.0  |
| eslint-plugin-import      | ^2.18.2           | ^2.20.2 |
| eslint-plugin-jsx-a11y    | ^6.2.3            | ^6.2.3  |
| eslint-plugin-react       | ^7.14.3           | ^7.20.0 |
| eslint-plugin-react-hooks | ^1.7.0            | ^4.0.4  |