upgrade dropdown

package.json

 {
   "name": "antd",
-  "version": "0.10.0-beta6",
+  "version": "0.10.0-beta7",
   "stableVersion": "0.9.1",
   "title": "Ant Design",
   "description": "一个 UI 设计语言",
@@ -42,7 +42,7 @@
     "rc-checkbox": "~1.1.1",
     "rc-collapse": "~1.3.0",
     "rc-dialog": "~5.1.0",
-    "rc-dropdown": "~1.3.3",
+    "rc-dropdown": "~1.4.0",
     "rc-form-validation": "~2.4.7",
     "rc-input-number": "~2.1.2",
     "rc-menu": "~4.6.2",

style/components/dropdown.less

@@ -100,6 +100,24 @@
       }
     }
   }
+
+  &.slide-up-enter.slide-up-enter-active&-placement-bottomLeft,
+  &.slide-up-appear.slide-up-appear-active&-placement-bottomLeft {
+    animation-name: antSlideUpIn;
+  }
+
+  &.slide-up-enter.slide-up-enter-active&-placement-topLeft,
+  &.slide-up-appear.slide-up-appear-active&-placement-topLeft {
+    animation-name: antSlideDownIn;
+  }
+
+  &.slide-up-leave.slide-up-leave-active&-placement-bottomLeft {
+    animation-name: antSlideUpOut;
+  }
+
+  &.slide-up-leave.slide-up-leave-active&-placement-topLeft {
+    animation-name: antSlideDownOut;
+  }
 }
 
 .@{dropdown-prefix-cls}-link {