Remove PyOpenSSL backends (except for openssl_pkcs12) (#273)

* Remove Ubuntu 16.04 (Xenial Xerus) from CI.

* Removing PyOpenSSL backend from everywhere but openssl_pkcs12.

* Remove PyOpenSSL support from module_utils that's not needed for openssl_pkcs12.

* Add changelog fragment.

tests/integration/targets/openssl_publickey/tasks/impl.yml

@@ -90,7 +90,7 @@
   openssl_privatekey:
     path: '{{ remote_tmp_dir }}/privatekey3.pem'
     passphrase: ansible
-    cipher: aes256
+    cipher: auto
     size: '{{ default_rsa_key_size }}'
 
 - name: "({{ select_crypto_backend }}) Generate publickey3 - with passphrase protected privatekey"

tests/integration/targets/openssl_publickey/tasks/main.yml

@@ -15,33 +15,6 @@
       path: '{{ remote_tmp_dir }}/privatekey_autodetect_public.pem'
       privatekey_path: '{{ remote_tmp_dir }}/privatekey_autodetect.pem'
 
-  when: |
-    pyopenssl_version.stdout is version('16.0.0', '>=') or
-    cryptography_version.stdout is version('1.2.3', '>=')
-
-- block:
-  - name: Running tests with pyOpenSSL backend
-    include_tasks: impl.yml
-    vars:
-      select_crypto_backend: pyopenssl
-
-  - import_tasks: ../tests/validate.yml
-    vars:
-      select_crypto_backend: pyopenssl
-
-  when: pyopenssl_version.stdout is version('16.0.0', '>=')
-
-- name: Remove output directory
-  file:
-    path: "{{ remote_tmp_dir }}"
-    state: absent
-
-- name: Re-create output directory
-  file:
-    path: "{{ remote_tmp_dir }}"
-    state: directory
-
-- block:
   - name: Running tests with cryptography backend
     include_tasks: impl.yml
     vars: