bash completion replaces underscores with dashes

[noqqe]

Hi,

since I've upgraded to click 7.0 the bash completion replaces underscores (_) in command names with dashes (-)

@click.command(short_help="Delete a group")
@click.option("groupname", '-g', '--group', type=str, required=True)
@click.option("--yes", is_flag=True, default=False)
@click.pass_context
def delete_group(ctx, yes, groupname):
    """
    Deletes a group identified by its short ID

the help message it looks like this:

Options:
  --version                   Show the version and exit.
  -e, --env [prod|stage|dev]  Choose environment to execute commands
  -h, --help                  Show this message and exit.

Commands:
  create_project          Creates a new project
  delete_group            Delete a group
  [...]

Gif example here:

[ThiefMaster]

Click 7 uses dashes instead of underscores in command names (which is actually more common in CLIs). See #1123