##### 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 -->


''' tests that GalaxyCLI exits with the error specified if the --ignore-errors flag is not used '''
        gc = GalaxyCLI(args=["ansible-galaxy", "install", "--server=None", "fake_role_name"])
        with patch.object(ansible.utils.display.Display, "display", return_value=None) as mocked_display:
            
            self.assertRaises(AnsibleError, gc.run)
            self.assertTrue(mocked_display.called_once_with("- downloading role 'fake_role_name', owned by "))
    def test_exit_without_ignore_with_flag(self):
        ''' tests that GalaxyCLI exits without the error specified if the --ignore-errors flag is used  '''
        
        gc = GalaxyCLI(args=["ansible-galaxy", "install", "--server=None", "fake_role_name", "--ignore-errors"])
        with patch.object(ansible.utils.display.Display, "display", return_value=None) as mocked_display:
            gc.run()
            self.assertTrue(mocked_display.called_once_with("- downloading role 'fake_role_name', owned by "))
    def test_parse_no_action(self):
        ''' testing the options parser when no action is given '''
        gc = GalaxyCLI(args=["ansible-galaxy", ""])
        self.assertRaises(SystemExit, gc.parse)
    def test_parse_invalid_action(self):
        ''' testing the options parser when an invalid action is given '''
        gc = GalaxyCLI(args=["ansible-galaxy", "NOT_ACTION"])
        self.assertRaises(SystemExit, gc.parse)
    def test_parse_delete(self):
        ''' testing the options parser when the action 'delete' is given '''
        gc = GalaxyCLI(args=["ansible-galaxy", "delete", "foo", "bar"])
        gc.parse()
        self.assertEqual(context.CLIARGS['verbosity'], 0)
    def test_parse_import(self):