Speed up tests (#153)

* Improve openssh_* tests.

* Use 2048 instead of 4096 bit keys in many places.

ci_complete

* Parameterize default RSA key length for tests.

* Reduce default RSA key size to 1024.

ci_complete

* Fix error.

ci_complete

* Use variable more often.

* Use 2048 bits for RSA keys for certificates on RHEL8 and CentOS8.

ci_complete

* Fix missing constant.

ci_complete

* Print default key sizes.

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

@@ -96,3 +96,7 @@
 - name: Register cryptography version
   command: "{{ ansible_python.executable }} -c 'import cryptography; print(cryptography.__version__)'"
   register: cryptography_version
+
+- name: Print default key sizes
+  debug:
+    msg: "Default RSA key size: {{ default_rsa_key_size }} (for certificates: {{ default_rsa_key_size_certifiates }})"