Remove usage of b64encode in lookup from Vault tests.

There are some issues using a combination of `lookup('file')` and the
`b64encode` filter in Ansible, making tests unstable. This change
removes the usage of b64encode when loading public and private keys
from files in the Vault test playbooks.

tests/vault/tasks_vault_members.yml

@@ -25,9 +25,9 @@
   - name: Ensure vault is present
     ipavault:
       ipaadmin_password: SomeADMINpassword
-      name: "{{vault.name}}"
-      vault_type: "{{vault.vault_type}}"
-      public_key: "{{lookup('file', 'private.pem', rstrip=False) | b64encode}}"
+      name: "{{ vault.name }}"
+      vault_type: "{{ vault.vault_type }}"
+      public_key: "{{lookup('file', 'A_private.b64')}}"
     register: result
     failed_when: not result.changed
     when: vault.vault_type == 'asymmetric'