PUT request with no response body returns error

[a88zach]

I'm using the reactiveSIM/deactivateSIM API methods. Both of these methods issue a PUT request and return a 200 without a response body. However, the response handler is trying to convert the empty body to JSON and fails.

https://github.com/particle-iot/particle-api-js/blob/master/src/Agent.js#L188

The call to particle is successful, but the method errors