remove build gulpfile.js

build/gulpfile.js

-/*---------------------------------------------------------------------------------------------
- *  Copyright (c) Microsoft Corporation. All rights reserved.
- *  Licensed under the MIT License. See License.txt in the project root for license information.
- *--------------------------------------------------------------------------------------------*/
-
-var gulp = require('gulp');
-var tsb = require('gulp-tsb');
-var util = require('./lib/util');
-var watcher = require('./lib/watch');
-var assign = require('object-assign');
-
-var compilation = tsb.create(assign({ verbose: true }, require('./tsconfig.json').compilerOptions));
-
-gulp.task('compile', function() {
-	return gulp.src('**/*.ts', { base: '.' })
-		.pipe(compilation())
-		.pipe(gulp.dest(''));
-});
-
-gulp.task('watch', function() {
-	var src = gulp.src('**/*.ts', { base: '.' });
-
-	return watcher('**/*.ts', { base: '.' })
-		.pipe(util.incremental(compilation, src))
-		.pipe(gulp.dest(''));
-});
-
-gulp.task('default', ['compile']);