Remove composer warning by setting proper env variables

Signed-off-by: Riddhesh Sanghvi <riddheshsanghvi96@gmail.com>

Author: mrrobot47

src/Admin_Tools_Command.php

@@ -245,6 +245,8 @@ private function move_config_file( $template_file, $config_file ) {
 	private function composer_install( $tool_path ) {
 
 		putenv( 'COMPOSER_HOME=' . EE_VENDOR_DIR . '/bin/composer' );
+		putenv( 'COMPOSER_CACHE_DIR=/dev/null' );
+		putenv( 'COMPOSER_ALLOW_SUPERUSER=1' );
 		chdir( $tool_path );
 		$input       = new ArrayInput( array( 'command' => 'update' ) );
 		$application = new Application();