fix: update label position when value is added in an empty text field (#212)

fixes issue #140

Author: tychenjiajun

components/text-field/TextField.vue

@@ -123,6 +123,9 @@ export default {
     },
     valid () {
       this.mdcTextField.valid = this.valid
+    },
+    value () {
+      this.mdcTextField.value = this.value
     }
   },
   mounted () {