update datepicker demo

components/datepicker/index.jsx

@@ -78,6 +78,7 @@ export default React.createClass({
         value={this.state.value}
         defaultValue={this.props.defaultValue}
         prefixCls="ant-calendar-picker"
+        style={this.props.style}
         onChange={this.handleChange}>
         <input
           placeholder={this.props.placeholder}

components/datepicker/index.md

@@ -30,9 +30,6 @@
 | size         | 输入框大小，`lg`代表高为32px，`sm`代表高为22px，默认28px      | string   | 无        |
 
 <style>
-.code-box-demo .ant-calendar-picker-input {
-  width: 200px;
-}
 .code-box-demo .ant-calendar-picker {
   margin: 0 12px 12px 0;
 }