Fix ElementMixin route

gulpfile.js

@@ -56,7 +56,7 @@ gulp.task('lint:css', function() {
 
 gulp.task('version:check', function() {
   const expectedVersion = new RegExp('^' + require('./package.json').version + '$');
-  return gulp.src(['*.html'])
+  return gulp.src(['src/*.html'])
     .pipe(htmlExtract({sel: 'script'}))
     .pipe(find(/static get version.*\n.*/))
     .pipe(clip()) // Remove non-matching files
@@ -76,8 +76,8 @@ gulp.task('version:update', ['version:check'], function() {
   if (!newversion) {
     throw new 'New version must be given as a npm_package_version environment variable.';
   }
-  return gulp.src(['*.html'])
+  return gulp.src(['src/*.html'])
     .pipe(replace(oldversion, newversion))
-    .pipe(gulp.dest('.'))
+    .pipe(gulp.dest('src/.'))
     .pipe(git.add());
 });

src/vaadin-upload.html

@@ -123,7 +123,7 @@
         }
 
         static get version() {
-          return '3.0.0';
+          return '4.0.0-alpha1';
         }
 
         static get properties() {