Robo command to build a release zip for Composer package.

RoboFile.php

<?php

class RoboFile extends \Robo\Tasks {

	/**
	 * Creates release zip
	 *
	 * @param string $package Composer package in vendor/name format.
	 * @param string $version Version to build.
	 */
	public function release( $package, $version = 'dev-master' ) {

		list( $vendor, $name ) = explode( '/', $package );

		if ( empty( $vendor ) || empty( $name ) ) {
			return;
		}

		$this->_mkdir( 'release' );

		$this->taskExec( "composer create-project {$package} {$name} {$version}" )
		     ->dir( __DIR__ . '/release' )
		     ->arg( '--prefer-dist' )
		     ->arg( '--no-dev' )
		     ->run();

		$this->taskExec( 'composer remove composer/installers --update-no-dev' )
		     ->dir( __DIR__ . "/release/{$name}" )
		     ->run();

		$this->taskExec( 'composer dump-autoload --optimize' )
		     ->dir( __DIR__ . "/release/{$name}" )
		     ->run();

		$zipFile = "release/{$name}-{$version}.zip";

		$this->_remove( $zipFile );

		$this->taskPack( $zipFile )
		     ->addDir( $name, "release/{$name}" )
		     ->run();

		if ( ! empty( $name ) ) {
			$this->_deleteDir( "release/{$name}" );
		}
	}
}