fix interface of runMode

packages/codemirror/src/mode.ts

@@ -25,7 +25,7 @@ declare var require: any;
  * Running a CodeMirror mode outside of an editor.
  */
 export
-function runMode(code: string, mode: modespec | string, el: HTMLElement): void {
+function runMode(code: string, mode: string, el: HTMLElement): void {
   CodeMirror.runMode(code, mode, el);
 }