TypeError thrown when response status is 204 No Content

[ajlozier]

When making a call such as:

hyperwalletManager.getHyperwallet().listUsers({ "email" : emailAddress }, function(err, users){
   ...
});

A TypeError is thrown when no results are returned, due to the fact that the 204 No Content response does not include a "Content-Type" header.

TypeError: Cannot read property 'indexOf' of undefined
      at /Users/aaron/WaitrInc/hyperwallet-node-sdk/src/utils/ApiClient.js:175:88

The following conditional does not check the status code before executing indexOf against the non-existent res.header["content-type"] array.

https://github.com/hyperwallet/node-sdk/blob/master/src/utils/ApiClient.js#L175

I have a PR which fixes this issue and also includes an additional test to cover this case.

[ajlozier]

This issue still seems to be present in the npm module. Is there a build pending?