Refactor Axios request

[JeffLoucks]

• Mailchimp requests are failing in dracula and I traced it back to requests not being fulfilled in this library
• It looks like when this was refactored from using the deprecated request library that it was still using the same arguments for request and not axios. request takes a config and a call back and looks like this:

request(config, function(resp, err) {
  // handle resp or error in callback
})

While axios looks like this:

axios(config)
  .then((resp) => //handle resp)
  .catch((err) => //handle err)

So, this PR is my attempt to use axios as their docs intend to see if it resolves some of our mailchimp issues.

[krcummings1]

LGTM! Thanks for finding and fixing this!