Merge branch 'help_custom' into 'master'

Improve the help option on all Bob click commands

Closes #59

See merge request !84

bob/extension/scripts/main_cli.py

@@ -9,7 +9,8 @@ logger = setup('bob')
 
 
 @with_plugins(pkg_resources.iter_entry_points('bob.cli'))
-@click.group(cls=AliasedGroup)
+@click.group(cls=AliasedGroup,
+             context_settings=dict(help_option_names=['-?', '-h', '--help']))
 def main():
   """The main command line interface for bob. Look below for available
   commands."""