[explicit-function-return-type] Rule doesn't work with class arrow methods

[slikts]

Repro

{
  "rules": {
    "@typescript-eslint/explicit-function-return-type": "error"
  }
}

export class Foo {
  bar() { return 123; } // Error
  baz = () => 123; // Missing error
}
export const foo = () => 123; // Error

Expected Result

Class arrow method with no return type annotation should be an error.

Actual Result

No error.

Additional Info

Versions

package	version
@typescript-eslint/eslint-plugin	1.4.2
@typescript-eslint/parser	1.4.2
TypeScript	3.3.3
ESLint	5.14.1