Fix AZP tests, add current_container_facts module (#48)

* Add new facts module for determining whether the module is running inside a container or not.

* Add containers to main network.

* Fix running tests locally with newer docker.

* Simplify setup_openssl to only install cryptography.

* Add alias in network.

* Make sure to upgrade cryptography to something more sensible on Ubuntu 16.04.

* Don't jump through hoops for bridge.

* Try to use other IPv4 nets.

* Improve module docs.

tests/integration/targets/setup_docker_registry/tasks/setup.yml

@@ -44,6 +44,15 @@
       name: '{{ docker_registry_container_name_registry }}'
       image: "{{ docker_test_image_registry }}"
       ports: 5000
+      network_mode: '{{ current_container_network_ip | default(omit, true) }}'
+      # We need to define the alias `real-registry` here because the global `links`
+      # option for the NGINX containers (see setup-frontend.yml) does not work when
+      # using networks.
+      networks: >-
+        {{
+          [dict([['name', current_container_network_ip], ['aliases', ['real-registry']]])]
+          if current_container_network_ip not in ['', 'bridge'] else omit
+        }}
     register: registry_container
 
   - name: Get registry URL