How can I tell Guzzle to safely ignore ssl.certificate_authority in Behat testing? (Development server)
After reading on https://github.com/Behat/MinkExtension/blob/master/doc/index.rst#drivers, I tried the following in the behat.yml file. 

default:
  suites:
    default:
      contexts:
        - FeatureContext
        - Drupal\DrupalExtension\Context\DrupalContext
        - Drupal\DrupalExtension\Context\MinkContext
  extensions:
    Behat\MinkExtension:
      goutte:
        guzzle_parameters:
          verify: false
      selenium2: ~
      base_url: http://localhost
    Drupal\DrupalExtension:
      blackbox: ~
      api_driver: 'drupal'
      drush:
        alias: 'local'
      drupal:
        drupal_root: '/var/www/html'


It worked.

I needed to find out how to tell Guzzle/cURL to not worry about validating any CERT. Again, I would not do this under a production server, but for the sake of a local development environment, I'd give it a go.