use babel-preset-env

.babelrc

 {
-  "presets": ["es2015", "stage-2"],
+  "presets": [
+    ["env", { "modules": false }],
+    "stage-2"
+  ],
   "plugins": ["transform-runtime"],
   "comments": false
 }

package.json

@@ -43,7 +43,7 @@
     "babel-eslint": "7.2.3",
     "babel-loader": "7.0.0",
     "babel-plugin-transform-runtime": "6.23.0",
-    "babel-preset-es2015": "6.24.1",
+     "babel-preset-env": "1.5.2",
     "babel-preset-stage-2": "6.24.1",
     "babel-register": "6.24.1",
     "chalk": "1.1.3",

src/directive/sticky.js

-(function() {
-  const vueSticky = {};
-  let listenAction;
-  vueSticky.install = Vue => {
+const vueSticky = {};
+let listenAction;
+vueSticky.install = Vue => {
   Vue.directive('sticky', {
     inserted(el, binding) {
       const params = binding.value || {},
@@ -86,14 +85,7 @@
       window.removeEventListener('scroll', listenAction)
     }
   })
-  };
-  if (typeof exports == 'object') {
-    module.exports = vueSticky
-  } else if (typeof define == 'function' && define.amd) {
-    define([], () => vueSticky)
-  } else if (window.Vue) {
-    window.vueSticky = vueSticky;
-    Vue.use(vueSticky)
-  }
-}());
+};
+
+export default vueSticky
 

src/directive/waves.js

 import './waves.css';
-(function() {
-  const vueWaves = {};
-  vueWaves.install = (Vue, options = {}) => {
+
+const vueWaves = {};
+vueWaves.install = (Vue, options = {}) => {
   Vue.directive('waves', {
     bind(el, binding) {
       el.addEventListener('click', e => {
@@ -41,14 +41,7 @@ import './waves.css';
       }, false);
     }
   })
-  };
-  if (typeof exports == 'object') {
-    module.exports = vueWaves
-  } else if (typeof define == 'function' && define.amd) {
-    define([], () => vueWaves)
-  } else if (window.Vue) {
-    window.vueWaves = vueWaves;
-    Vue.use(vueWaves)
-  }
-}());
+};
+
+export default vueWaves;