use modifier for v-on key filter

Author: yyx990803

src/directives/on.js

@@ -9,7 +9,7 @@ module.exports = {
   bind: function () {
     // 1.0.0 key filter
     var rawArg = this.arg
-    var keyIndex = rawArg.indexOf(':')
+    var keyIndex = rawArg.indexOf('.')
     if (keyIndex > -1) {
       this.arg = rawArg.slice(0, keyIndex)
       this.key = rawArg.slice(keyIndex + 1)

test/unit/specs/directives/on_spec.js

@@ -74,7 +74,7 @@ if (_.inBrowser) {
     it('with key filter (new syntax)', function (done) {
       new Vue({
         el: el,
-        template: '<a @keyup:enter="test">{{a}}</a>',
+        template: '<a @keyup.enter="test">{{a}}</a>',
         data: {a: 1},
         methods: {
           test: function () {