build: bump flow version

package.json

@@ -82,7 +82,7 @@
     "eslint-plugin-jasmine": "^2.2.0",
     "eslint-plugin-vue-libs": "^1.2.0",
     "file-loader": "^0.11.2",
-    "flow-bin": "^0.48.0",
+    "flow-bin": "^0.54.0",
     "hash-sum": "^1.0.2",
     "he": "^1.1.1",
     "http-server": "^0.10.0",

src/core/util/env.js

@@ -86,7 +86,7 @@ export const nextTick = (function () {
   // UIWebView in iOS >= 9.3.3 when triggered in touch event handlers. It
   // completely stops working after triggering a few times... so, if native
   // Promise is available, we will use it:
-  /* istanbul ignore if */
+  /* istanbul ignore if */ // $flow-disable-line
   if (typeof Promise !== 'undefined' && isNative(Promise)) {
     var p = Promise.resolve()
     var logError = err => { console.error(err) }
@@ -141,6 +141,7 @@ export const nextTick = (function () {
       pending = true
       timerFunc()
     }
+    // $flow-disable-line
     if (!cb && typeof Promise !== 'undefined') {
       return new Promise((resolve, reject) => {
         _resolve = resolve
@@ -150,7 +151,7 @@ export const nextTick = (function () {
 })()
 
 let _Set
-/* istanbul ignore if */
+/* istanbul ignore if */ // $flow-disable-line
 if (typeof Set !== 'undefined' && isNative(Set)) {
   // use native Set when available.
   _Set = Set