Issue:
An error is thrown on build when using the object spread + $Exact flow utility type

Example:

type B = number

export type MyType = {
  a: string,
  ...$Exact<B>
}

> yarn documentation readme ./index.js --document-exported

TypeError: Cannot read property 'name' of undefined at /Users/andrewdelprete/path/to/node_modules/documentation/src/infer/properties.js:57:63

• What version of documentation.js are you using?: v13.0.0

• How are you running documentation.js (on the CLI, Node.js API, Grunt, other?): CLI