TypeError: canvas.createSyncPNGStream is not a function

## Issue
`node benchmark/run.js` throws `TypeError: canvas.createSyncPNGStream is not a function`

## Steps to Reproduce
```sh
node benchmark/run.js
```

## Your Environment
* Version of node-canvas
`canvas@2.7.0`

* Environment
`node v13.11.0`
`macOS 10.15.6`