Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires symfony/phpunit-bridge ^6 -> satisfiable by symfony/phpunit-bridge[v6.0.0, ..., v6.4.10]. - symfony/phpunit-bridge[v6.0.0, ..., v6.4.10] require php >=7.1.3 -> your php version (5.3.29) does not satisfy that requirement.

Process completed with exit code 2.

Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires symfony/phpunit-bridge ^6 -> satisfiable by symfony/phpunit-bridge[v6.0.0, ..., v6.4.10]. - symfony/phpunit-bridge[v6.0.0, ..., v6.4.10] require php >=7.1.3 -> your php version (5.5.38) does not satisfy that requirement.

Process completed with exit code 2.

Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires symfony/phpunit-bridge ^6 -> satisfiable by symfony/phpunit-bridge[v6.0.0, ..., v6.4.10]. - symfony/phpunit-bridge[v6.0.0, ..., v6.4.10] require php >=7.1.3 -> your php version (5.6.40) does not satisfy that requirement.

Process completed with exit code 2.

The job was canceled because "_5_3" failed.

The job was canceled because "_5_3" failed.

The job was canceled because "_5_3" failed.

The job was canceled because "_5_3" failed.

The job was canceled because "_5_3" failed.

The operation was canceled.

The job was canceled because "_5_3" failed.

The job was canceled because "_5_3" failed.

The operation was canceled.

The job was canceled because "_5_3" failed.

The operation was canceled.

The job was canceled because "_5_3" failed.

The operation was canceled.

The job was canceled because "_5_3" failed.

The operation was canceled.

The job was canceled because "_5_3" failed.