Fixes trove help command

Reason:
- trove help output misplaces the position of "<subcommand> ..."
  from bottom to top.
- This behavior is because of formatting done to
  Print positionals before optionals.

Changes:
- Sequence fixed in trove help output.

Change-Id: I8aff2eec9f915a7ec1960b67ee7ba8423624aad6
Closes-Bug: #1260332

troveclient/shell.py

@@ -614,7 +614,14 @@ class OpenStackHelpFormatter(argparse.HelpFormatter):
                 if len(prefix) + len(prog) <= 0.75 * text_width:
                     indent = ' ' * (len(prefix) + len(prog) + 1)
                     if pos_parts:
-                        lines = get_lines([prog] + pos_parts, indent, prefix)
+                        if prog == 'trove':
+                            # "trove help" called without any subcommand
+                            lines = get_lines([prog] + opt_parts, indent,
+                                              prefix)
+                            lines.extend(get_lines(pos_parts, indent))
+                        else:
+                            lines = get_lines([prog] + pos_parts, indent,
+                                              prefix)
                             lines.extend(get_lines(opt_parts, indent))
                     elif opt_parts:
                         lines = get_lines([prog] + opt_parts, indent, prefix)