Callback results is undefined

Dear @fdesjardins unfortunately last few days package is returning `undefine`
At example.js:
```
const notams = require('notams')

notams.fetch([ 'PADK', 'PADU' ], { format: 'DOMESTIC' }).then(results => {
	console.log(JSON.stringify(results, null, 2))
})
```
npm --save install
node example.js