Check ExampleEnvironmentVariablesAreSet doesn't check actual environment variables

[rick-nu]

What

The check ExampleEnvironmentVariablesAreSet only compares the .env.example with the .env file. It would make sense to check if actual environment variables are set too.

Why

We're running a laravel project in Kubernetes. In the production container there is no .env file, but instead the environment variables are set on the container directly. We want to run the ExampleEnvironmentVariablesAreSet as "init container" to be sure that the container doesn't start with missing environment variables.

Proposed fix

Also check the actual environment variables (getenv()), don't just compare the .env file.

[mtolhuys]

Just a suggestion: maybe checking where env() get's called inside the config folder and checking if the contents of those are set could be a cool addition to this.