`st2 pack install` will ignore failures when installing multiple packs

SUMMARY

If I attempt to install multiple packs using st2 pack install, and one of those packs is non-existent, it will silently ignore the failure.

ISSUE TYPE

• Bug Report

STACKSTORM VERSION

st2 3.0dev (d86747c), on Python 2.7.12

OS / ENVIRONMENT / INSTALL METHOD

one-line install.

STEPS TO REPRODUCE

extreme@ubuntu:~$ st2 pack install foobar acos

For the "foobar, acos" packs, the following content will be registered:

rules     |  0
sensors   |  0
aliases   |  0
actions   |  19
triggers  |  0

Installation may take a while for packs with many items.

	[ succeeded ] download pack
	[ succeeded ] make a prerun
	[ succeeded ] install pack dependencies
	[ succeeded ] register pack

+-------------+-----------------------------------------------+
| Property    | Value                                         |
+-------------+-----------------------------------------------+
| name        | acos                                          |
| description | Manage ACOS-based appliances of A10 Networks. |
| version     | 0.2.5                                         |
| author      | Hiroyasu OHYAMA                               |
+-------------+-----------------------------------------------+
extreme@ubuntu:~$

EXPECTED RESULTS

I expected some error message about "pack foobar not found", similar to if I had just tried st2 pack install foobar

ACTUAL RESULTS

Install completes 'successfully', since one pack install works.