v5 support for laravel 7

[Aslam97]

Problem 1
    - rinvex/laravel-subscriptions[v5.0.0, ..., v5.0.3] require illuminate/console ^8.0.0 || ^9.0.0 -> found illuminate/console[dev-master, v8.0.0, ..., 8.x-dev, 9.x-dev (alias of dev-master)] but these were not loaded, likely because it conflicts with another require.
    - Root composer.json requires rinvex/laravel-subscriptions ^5.0 -> satisfiable by rinvex/laravel-subscriptions[v5.0.0, v5.0.1, v5.0.2, v5.0.3].

[Omranic]

If you want to use this package with older version of Laravel, then try v4.x

For the latest release, we're only supporting latest stable release of Laravel which is currently v8.x