Add new autocomplete_commands toggle; fixes #34

[chrisarcand]

Added a new autocomplete_commands <boolean> toggle to GLI, released in 2.13.0 (form this PR: davetron5000/gli#211). This fixes the issue of partial commands doing bad things, such as op deploy -> op deployable.

QA:

Easiest QA is just building this branch locally, installing it in a project, and trying sync. Should not execute sync-branch but instead throw an UnknownCommand error.

[chrisarcand]

@anfleene @NickLaMuro

[anfleene]

you should use this to test that it doesn't autocomplete https://github.com/coderanger/rspec-command/blob/master/README.md

[anfleene]

code looks good I'll QA it when I get into the office

[chrisarcand]

@anfleene This is a 3rd party dependency 😉 Tests are in the project from whence it came.
https://github.com/davetron5000/gli/blob/gli-2/test/tc_command_finder.rb

But whoa, I didn't know about rspec-command, we should use that for applicable items in this project for sure.

[anfleene]

fair enough. yeah I just ran into it this morning looks awesome

[anfleene]

QA passes 🐑 🇮🇹

[anfleene]

@chrisarcand Have you released op before?

[chrisarcand]

@anfleene Nein. I need rubygems access and additional info if there's anything special other than just being a gem.