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##### SUMMARY

The Git module encourages use of `StrictHostKeyChecking=no` with SSH, which makes the connection vulnerable to a MITM attack.

##### ISSUE TYPE

OpenSSH 7.5+ (2017-03-20) added a safer option which automatically accepts the key on first use but will not allow a MITM on subsequent connections: `StrictHostKeyChecking=accept-new` 

https://man.openbsd.org/ssh_config#StrictHostKeyChecking

It would be great if Ansible encouraged use of that mode by default in the documentation and to implement features such as the Git module's [`accept_hostkey`](https://github.com/ansible/ansible/blob/323d2adfcce9a53e906c2c4a40f6ac5fb32a0e68/lib/ansible/modules/git.py#L1103-L1108) feature.

##### ANSIBLE VERSION

```paste below
N/A
```

##### COMPONENT NAME
* `/modules/source_control/git.py`


if os.environ.get("GIT_SSH"):
        del os.environ["GIT_SSH"]
    os.environ["GIT_SSH"] = ssh_wrapper
    if os.environ.get("GIT_KEY"):
        del os.environ["GIT_KEY"]
    if key_file:
        os.environ["GIT_KEY"] = key_file
    if os.environ.get("GIT_SSH_OPTS"):
        del os.environ["GIT_SSH_OPTS"]
    if ssh_opts:
        os.environ["GIT_SSH_OPTS"] = ssh_opts
def get_version(module, git_path, dest, ref="HEAD"):