Pipenv local editable packages won't deploy

I'm using a pipfile with a section like this
```
[packages.common]
editable = true
path = "./../common"
```

Gives the error

> STDERR: ERROR: Invalid requirement: './../common' (from line 1 of /var/task/requirements.txt)
>   Hint: It looks like a path. File './../common' does not exist.

#314 seems to be similar, the only difference is my package is a sibling folder