gulp-sass add more methods

- logError
 - sync

gulp-sass/gulp-sass-tests.ts

@@ -12,5 +12,6 @@ gulp.task('sass', function () {
 gulp.task('sass', function () {
     gulp.src('./scss/*.scss')
         .pipe(sass({errLogToConsole: true}))
+        .pipe(sass.sync())
         .pipe(gulp.dest('./css'));
 });

gulp-sass/gulp-sass.d.ts

@@ -45,6 +45,8 @@ declare module "gulp-sass" {
 
     interface Sass {
         (opts?: Options): NodeJS.ReadWriteStream;
+        logError(error?: string): void;
+        sync(options?: Options): NodeJS.ReadWriteStream;
     }
 
     var _tmp: Sass;