Revert "Commit updated Javascript packages"

This reverts commit a88734348a.

build/javascript/node_modules/is-function/index.js

@@ -1,18 +0,0 @@
-module.exports = isFunction
-
-var toString = Object.prototype.toString
-
-function isFunction (fn) {
-  if (!fn) {
-    return false
-  }
-  var string = toString.call(fn)
-  return string === '[object Function]' ||
-    (typeof fn === 'function' && string !== '[object RegExp]') ||
-    (typeof window !== 'undefined' &&
-     // IE8 and below
-     (fn === window.setTimeout ||
-      fn === window.alert ||
-      fn === window.confirm ||
-      fn === window.prompt))
-};