-sh-4.1$ composer update
Your version of PHP, 5.4.13, is affected by CVE-2013-6420 and cannot safely perform certificate validation, we strongly suggest you upgrade.
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - This package requires php >=5.6.4 but your PHP version (5.4.13) does not satisfy that requirement.
  Problem 2
    - Installation request for laravel/tinker ~1.0 -> satisfiable by laravel/tinker[v1.0.0].
    - laravel/tinker v1.0.0 requires php >=5.5.9 -> your PHP version (5.4.13) does not satisfy that requirement.
  Problem 3
    - laravel/framework v5.4.9 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.8 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.7 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.6 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.5 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.4 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.3 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.23 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.22 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.21 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.20 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.2 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.19 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.18 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.17 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.16 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.15 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.14 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.13 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.12 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.11 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.10 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.1 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - laravel/framework v5.4.0 requires php >=5.6.4 -> your PHP version (5.4.13) does not satisfy that requirement.
    - Installation request for laravel/framework 5.4.* -> satisfiable by laravel/framework[v5.4.0, v5.4.1, v5.4.10, v5.4.11, v5.4.12, v5.4.13, v5.4.14, v5.4.15, v5.4.16, v5.4.17, v5.4.18, v5.4.19, v5.4.2, v5.4.20, v5.4.21, v5.4.22, v5.4.23, v5.4.3, v5.4.4, v5.4.5, v5.4.6, v5.4.7, v5.4.8, v5.4.9].