Spin animate with tips (#2801)

* Spin 组件在显示 tip 时同时显示动画

* remove tip text when not exists

components/spin/index.tsx

@@ -103,7 +103,7 @@ export default class Spin extends React.Component<SpinProps, any> {
     const spinElement = (
       <div {...divProps} className={spinClassName}>
         <span className={`${prefixCls}-dot`} />
-        <div className={`${prefixCls}-text`}>{tip || '加载中...'}</div>
+        {tip ? <div className={`${prefixCls}-text`}>{tip}</div> : null}
       </div>
     );
 

components/spin/style/index.less

@@ -106,11 +106,6 @@
     .square(@spin-dot-size-lg);
   }
 
-  &-text,
-  &&-show-text &-dot {
-    display: none;
-  }
-
   &&-show-text &-text {
     display: block;
   }