Octorun JS refactor authentication methods

[StanleyGoldman]

Breakout of #617

• handleBasicAuthentication and handleTwoFactorAuthentication can be refactored
  Octorun Js #599 (review)

In Octorun the authentication methods in authentication.js are very similar and can be consolidated.

Unity/octorun/src/authentication.js

Line 11 in d05f08b

var handleBasicAuthentication = function (username, password, onSuccess, onRequiresTwoFa, onFailure) {

Unity/octorun/src/authentication.js

Line 46 in d05f08b

var handleTwoFactorAuthentication = function (username, password, twoFactor, onSuccess, onFailure) {