message: Add polyfill for IE. Fixes
diff: @@ -33,6 +33,13 @@ function deepMerge_(dest: any, src: any) {
  return dest;
  }
  +// polyfill for IE
  +if (!String.prototype.startsWith) {
  + String.prototype.startsWith = function(search, pos) {
  + return this.substr(!pos || pos < 0 ? 0 : +pos, search.length) === search;
  + };
  +}
  +
  export function isURL(s: string): boolean {
  return s.startsWith('http://') || s.startsWith('https://') || s.startsWith('//');
  }
  