Button: fix disabled attribute

examples/components/theme-picker.vue

@@ -97,7 +97,7 @@
           let green = parseInt(color.slice(2, 4), 16);
           let blue = parseInt(color.slice(4, 6), 16);
 
-          if (tint === 0) {
+          if (tint === 0) { // when primary color is in its rgb space
             return [red, green, blue].join(',');
           } else {
             red += Math.round(tint * (255 - red));

packages/button/src/button.vue

@@ -2,6 +2,8 @@
   <button
     class="el-button"
     @click="handleClick"
+    :disabled="disabled"
+    :autofocus="autofocus"
     :type="nativeType"
     :class="[
       type ? 'el-button--' + type : '',