Add support for Redis storage adapter

[zenire]

The need for using the Redis storage adapter may exist when users have deployed their Laravel application across multiple servers/instances (for example when using k8s). Using a shared storage adapter will prevent incorrect measurements.

laravel-prometheus/src/PrometheusServiceProvider.php

Line 36 in 7aa620d

return new CollectorRegistry(new InMemory(), false);

will have to be changed to add support for choosing storage adapters like InMemory() and Redis(). We can specify the adapter in config/prometheus.php and reuse the Laravel Redis connection details or specify a custom connection.

[Husseinhewehii]

injecting the Storage adapter is already handler by the package

in config/prometheus.php updating cache Key did the job for me, 'cache' => 'redis'