[eslint-config-kyt] Add eslint-plugin-jest

[tizmagik]

Add eslint-plugin-jest to our eslint-config-kyt preset.

This eslint plugin provides some helpful lint rules:

{
  "rules": {
    "jest/no-disabled-tests": "warn",
    "jest/no-focused-tests": "error",
    "jest/no-identical-title": "error",
  }
}