feat(warnings): Add "symbol" and "boolean" for "key" warning

Booleans as keys are supported since vuejs#6127 and symbols since vuejs#7271.
The warning should reflect that.

Author: mpawelski

packages/vue-server-renderer/build.dev.js

@@ -6862,7 +6862,7 @@ function _createElement (
     {
       warn(
         'Avoid using non-primitive value as key, ' +
-        'use string/number value instead.',
+        'use string/number/symbol/boolean value instead.',
         context
       );
     }

packages/weex-vue-framework/factory.js

@@ -3575,7 +3575,7 @@ function _createElement (
     if (!('@binding' in data.key)) {
       warn(
         'Avoid using non-primitive value as key, ' +
-        'use string/number value instead.',
+        'use string/number/symbol/boolean value instead.',
         context
       );
     }

src/core/vdom/create-element.js

@@ -74,7 +74,7 @@ export function _createElement (
     if (!__WEEX__ || !('@binding' in data.key)) {
       warn(
         'Avoid using non-primitive value as key, ' +
-        'use string/number value instead.',
+        'use string/number/symbol/boolean value instead.',
         context
       )
     }