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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`


description:
            - If C(yes), any modified files in the working
              repository will be discarded.  Prior to 0.7, this was always
              C(yes) and could not be disabled.  Prior to 1.9, the default was
              C(yes).
        type: bool
        default: 'no'
        version_added: "0.7"
    depth:
        description:
            - Create a shallow clone with a history truncated to the specified
              number or revisions. The minimum possible value is C(1), otherwise
              ignored. Needs I(git>=1.9.1) to work correctly.
        type: int
        version_added: "1.2"
    clone:
        description:
            - If C(no), do not clone the repository even if it does not exist locally.
        type: bool
        default: 'yes'
        version_added: "1.9"
    update:
        description:
            - If C(no), do not retrieve new revisions from the origin repository.
            - Operations like archive will work on the existing (old) repository and might
              not respond to changes to the options version or remote.
        type: bool
        default: 'yes'
        version_added: "1.2"
    executable: