Change gulp-build for gulp-concat

[alexol91]

Example:

gulp.task('build:angular', function () {
  return gulp.src('../app/index.html')
  .pipe(inject(
    gulp.src(['../app/app.js', '../app/components/**/*.js'])
    .pipe(concat('app.min.js'))
    .pipe(uglify())
    .pipe(gulp.dest('../app/')),
  ))
    .pipe(gulp.dest('../app'))

});