Cannot convert undefined or null to object

[AskAlice]

TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at Object.exports.getSuccessResponse (C:\Users\alice\AppData\Roaming\npm-cache\_npx\36204\node_modules\swagger-to-graphql\lib\swagger.js:13:30)
    at C:\Users\alice\AppData\Roaming\npm-cache\_npx\36204\node_modules\swagger-to-graphql\lib\swagger.js:185:35
    at Array.forEach (<anonymous>)
    at C:\Users\alice\AppData\Roaming\npm-cache\_npx\36204\node_modules\swagger-to-graphql\lib\swagger.js:158:28
    at Array.forEach (<anonymous>)
    at Object.exports.getAllEndPoints (C:\Users\alice\AppData\Roaming\npm-cache\_npx\36204\node_modules\swagger-to-graphql\lib\swagger.js:156:31)
    at Object.<anonymous> (C:\Users\alice\AppData\Roaming\npm-cache\_npx\36204\node_modules\swagger-to-graphql\lib\index.js:132:39)
    at step (C:\Users\alice\AppData\Roaming\npm-cache\_npx\36204\node_modules\swagger-to-graphql\lib\index.js:43:23)
    at Object.next (C:\Users\alice\AppData\Roaming\npm-cache\_npx\36204\node_modules\swagger-to-graphql\lib\index.js:24:53)

I seem to get that with this https://aperture.section.io/api/v1/swagger.yaml which i converted to json with swagger-codegen => http://in4.us/swagger.json

I thought it might be related to issue #20, but i changed all the responses to have a 200 and it still seemed to die