micahjon

/**
 * Loads javascript file by url and saves reference to it by name, so it's not loaded again
 * @param  {string} name Name of js library
 * @param  {string} url  Url to js library
 * @return {promise}     Resolves when library is loaded
 * 
 * Based on example by Brad Berger: https://bradb.net/blog/promise-based-js-script-loader/
 * Extended w/ global variable to keep track of previously loaded scripts.
 * Removed support for loading several independent scripts at once via Promise.all()
 *