##### SUMMARY
If you have executable files in your source code they are not kept in the tarball.

Could be related to https://github.com/ansible/ansible/blob/99d7f150873011e7515851db9b44ff486efa9d77/lib/ansible/galaxy/collection.py#L763

This was noticed as I had some auxiliary scripts in my repo.

Need to also consider scripts in `files/` if/when Collections support roles.

This seems to fail the "principal of least suprise"

**Proposal 1: Keep on stripping executable flags**

Add some line to the output
`WARNING: tests/coverage.sh: source file has executable flag, though this will be ignored in generated tar.gz`
Update developing a collection documentation page
Update integration tests to ensure that executable mode is always stripped.
Update code to link to this issue

**Proposal 2: Allow executible flags**

Update developing a collection documentation page
Update integration tests to ensure that executable mode is preserved
Update code to link to this issue
Changelog


##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
ansible-galaxy

##### ANSIBLE VERSION
```paste below
2.10
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

<!--- HINT: You can paste gist.github.com links for larger files -->


b'*.retry',
        b'tests/output',  
        to_bytes('{0}-{1}-*.tar.gz'.format(namespace, name)),  
    ]
    b_ignore_patterns += [to_bytes(p) for p in ignore_patterns]
    b_ignore_dirs = frozenset([b'CVS', b'.bzr', b'.hg', b'.git', b'.svn', b'__pycache__', b'.tox'])
    entry_template = {
        'name': None,
        'ftype': None,
        'chksum_type': None,
        'chksum_sha256': None,
        'format': MANIFEST_FORMAT
    }
    manifest = {
        'files': [
            {
                'name': '.',
                'ftype': 'dir',
                'chksum_type': None,
                'chksum_sha256': None,
                'format': MANIFEST_FORMAT,
            },
        ],
        'format': MANIFEST_FORMAT,
    }
    def _walk(b_path, b_top_level_dir):
        for b_item in os.listdir(b_path):
            b_abs_path = os.path.join(b_path, b_item)
            b_rel_base_dir = b'' if b_path == b_top_level_dir else b_path[len(b_top_level_dir) + 1:]
            b_rel_path = os.path.join(b_rel_base_dir, b_item)