mapbox_client.js

var loadScript = require('load-script'),
  R = require('ramda');

var getAWS = R.once(function() {
  return new Promise(function(resolve, reject) {
    if (typeof AWS !== 'undefined') {
      return resolve(AWS);
    }
    loadScript('bundle-aws.min.js', function(err) {
      if (err || typeof AWS === 'undefined') {
        return reject(err || new Error('An error occurred'));
      } else {
        resolve(AWS);
      }
    });
  });
});