Generate selfsigned certificate about dart-basic-utils

[Ephenodrom]

• id-kp-serverAuth = 1.3.6.1.5.5.7.3.1
• id-kp-clientAuth = 1.3.6.1.5.5.7.3.2
• id-kp-codeSigning = 1.3.6.1.5.5.7.3.3
• id-kp-emailProtection = 1.3.6.1.5.5.7.3.4
• id-kp-timeStamping = 1.3.6.1.5.5.7.3.8
• id-kp-OCSPSigning = 1.3.6.1.5.5.7.3.9

[gmpassos]

Add package coverage to generate coverage reports.

You can see shelf_letsencrypt project as reference:

• https://github.com/gmpassos/shelf_letsencrypt/blob/master/pubspec.yaml
• https://github.com/gmpassos/shelf_letsencrypt/blob/master/run_coverage.sh
• https://github.com/gmpassos/shelf_letsencrypt/blob/master/.github/workflows/dart.yml

https://app.codecov.io/gh/gmpassos/shelf_letsencrypt

[Ephenodrom]

@gmpassos Please checkout version 3.8.0 that contains a method to generate a self signed certificate. I testet it with PLESK and it worked fine.