fix: gulpfile.js missing done var in build task

Author: ni0ki

dist/angular-localForage.js

@@ -120,7 +120,7 @@
         } else {
           var deferred = $q.defer(),
             args = arguments,
-            localCopy = typeof Blob !== 'undefined' && value instanceof Blob ? value : angular.copy(value);
+            localCopy = typeof Blob !== 'undefined' && typeof ArrayBuffer !== 'undefined' && (value instanceof Blob || value instanceof ArrayBuffer) ? value : angular.copy(value);
 
           //avoid $promises attributes from value objects, if present.
           if(angular.isObject(localCopy) && angular.isDefined(localCopy.$promise)) {

dist/angular-localForage.min.js

@@ -34,7 +34,7 @@ gulp.task('build-files', function() {
     .pipe(gulp.dest('dist'));
 });
 
-gulp.task('build', ['karma'], function() {
+gulp.task('build', ['karma'], function(done) {
   runSequence('karma', 'build-files', done);
 });