npm install fails with ENOENT

[arnoschutijzer]

Hi there!

I just noticed a couple of our builds started breaking with the following error:

     [exec] npm ERR! code ENOENT
     [exec] npm ERR! syscall chmod
     [exec] npm ERR! path /frontend/node_modules/geojson-flatten/geojson-flatten
     [exec] npm ERR! errno -2
     [exec] npm ERR! enoent ENOENT: no such file or directory, chmod '/frontend/node_modules/geojson-flatten/geojson-flatten'
     [exec] npm ERR! enoent This is related to npm not being able to find a file.
     [exec] npm ERR! enoent 

Checking out this repository and running:

$ npm install && npm link

also results in the same error.

Removing the bin parameter from the package.json seems to be the correct fix here so I'll create a PR shortly.