No matching version found for dependencies@undefined

#### Issue description:
After converting yarn.lock to package-lock.json I run `npm install`.
output is
```
npm i
npm ERR! code ETARGET
npm ERR! notarget No matching version found for dependencies@undefined
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist.

```
_Disclaimer_
I reinstalled node_modules fresh using `yarn install`, then I used following command to convert `yarn.lock` `synp --source-file yarn.lock` and it ran correctly and created `package-lock.json`

#### Attaching files
`yarn.lock` https://pastebin.com/FZWC7mUS
`package-lock.json` https://ufile.io/3rsmr
`package.json` https://pastebin.com/9fMwYfGt

Start by reproducing the conversion with the attached yarn.lock and package.json, then run npm install against the generated package-lock.json. Inspect how synp represents dependencies during conversion; done means the generated lockfile no longer requests dependencies@undefined and npm install completes successfully.

Written by the indexing model from the issue text.