Properly mark check as failed for expired certificates

[JaZo]

Description

I fixed two bugs causing the check to crash on expired certificates and marking the check as success for expired certificates.

Motivation and context

When you check a domain with an expired certificate, the check crashes with the following exception:

Could not download certificate for host expired.badssl.com because Could not connect to expired.badssl.com:443.

Based on the documentation you should skip certificate verification when downloading expired certificates. Besides that, the logic to see if the certificate has expired is incorrect.

Current logic (bad)

echo Carbon::now()->addMonth()->diffInDays(); // 30
echo Carbon::now()->subMonth()->diffInDays(); // 30

New logic (correct)

echo Carbon::now()->diffInDays(Carbon::now()->addMonth(), false); // 31
echo Carbon::now()->diffInDays(Carbon::now()->subMonth(), false); // -29

How has this been tested?

I added new tests.

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

[VictoRD11]

Thanks <3

[JaZo]

You're welcome! Would you be so kind to add the hacktoberfest topic to the repository or the hacktoberfest-accepted label to this PR? 😃 You can find more info on https://hacktoberfest.com/participation/#pr-mr-details.