##### 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 -->


''' used for making a tarfile from a role directory '''
        
        try:
            tar = tarfile.open(output_file, "w:gz")
            tar.add(source_dir, arcname=os.path.basename(source_dir))
        except AttributeError:  
            pass
        finally:  
            tar.close()
    @classmethod
    def tearDownClass(cls):
        '''After tests are finished removes things created in setUpClass'''
        
        if os.path.exists(cls.role_dir):
            shutil.rmtree(cls.role_dir)
        if os.path.exists(cls.role_req):
            os.remove(cls.role_req)
        if os.path.exists(cls.role_tar):
            os.remove(cls.role_tar)
        if os.path.isdir(cls.role_path):
            shutil.rmtree(cls.role_path)
        os.chdir('/')
        shutil.rmtree(cls.temp_dir)
    def setUp(self):