How to use the gulp-git.add function in gulp-git

gulp.task('push', ['check-coverage', 'minify'], function(){
	var commitMessage = gulp.env.m || 'refactoring';
	console.log('Tests passed! Pushing code...');
	return gulp
		.src('./.')
		.pipe(git.add())
		.pipe(git.commit(commitMessage))
		.pipe(git.push());
});

gulp.task('git-commit', function(cb) {
  gulp.src('.')
    .pipe(git.add())
    .pipe(git.commit("bump to " + args.tag))
    .pipe(gcallback(cb))
});

gulp.task('release:commit', ['release:rebuild'], function() {
    return gulp.src(['./package.json', 'dist/**/*'])
            .pipe(git.add())
            .pipe(git.commit(versionAfterBump));
});

gulp.task('git-scripts', function () {
    return gulp.src(paths.scripts)
        .pipe(git.add());
});

gulp.task('git-site', function () {
    return gulp.src(paths.site.root)
        .pipe(git.add());
});