test-module: define ansible_version attribute

Executed command:

    ./hacking/test-module -m lib/ansible/modules/cloud/scaleway/scaleway_security_group.py -a ...

Fix this exception found while testing scaleway_security_group module:

    Traceback (most recent call last):
      File "~/debug_dir/__main__.py", line 240, in <module>
        main()
      File "~/debug_dir/__main__.py", line 236, in main
        core(module)
      File "~/debug_dir/__main__.py", line 209, in core
        api = Scaleway(module=module)
      File "~/debug_dir/ansible/module_utils/scaleway.py", line 58, in __init__
        'User-Agent': self.get_user_agent_string(module),
      File "~/debug_dir/ansible/module_utils/scaleway.py", line 99, in get_user_agent_string
        return "ansible %s Python %s" % (module.ansible_version, sys.version.split(' ')[0])
    AttributeError: 'AnsibleModule' object has no attribute 'ansible_version'

hacking/test-module

@@ -35,6 +35,7 @@ import sys
 import traceback
 import shutil
 
+from ansible.release import __version__
 import ansible.utils.vars as utils_vars
 from ansible.parsing.dataloader import DataLoader
 from ansible.parsing.utils.jsonify import jsonify
@@ -124,6 +125,7 @@ def boilerplate_module(modfile, args, interpreters, check, destfile):
     complex_args['_ansible_selinux_special_fs'] = C.DEFAULT_SELINUX_SPECIAL_FS
     complex_args['_ansible_tmpdir'] = C.DEFAULT_LOCAL_TMP
     complex_args['_ansible_keep_remote_files'] = C.DEFAULT_KEEP_REMOTE_FILES
+    complex_args['_ansible_version'] = __version__
 
     if args.startswith("@"):
         # Argument is a YAML file (JSON is a subset of YAML)