node.optional sometimes is on key, sometimes on ClassProperty

[duailibe]

What version of TypeScript are you using?

2.8.0-rc

What version of typescript-eslint-parser are you using?

14.0.0

What code were you trying to parse?

class X {
  foo?: string;
  "foo-bar"?: string;

What did you expect to happen?

Either the ClassProperty has optional: true or its key for both cases

What happened?

In the first case, optional: true is set on the key, and in the second case it's set on the ClassProperty

cc @JamesHenry