StackStorm/st2 — pull request #880 by Kami (2014-12-08 21:47:54+00:00)
Title: [WIP] Record action execution end time, various improvements and bug fixes

Records the time when an action has finished on the `ActionExcution` model via the `end_timestamp` attribute.

It also includes bug-fixes for various bugs I've encountered while testing it and improves formatting for iso date time fields returned in the CLI:

Before:

```
+--------------------------+------------+--------------+-----------+-----------------------------+-----------------------------+
| id | action | context.user | status | start_timestamp | end_timestamp |
+--------------------------+------------+--------------+-----------+-----------------------------+-----------------------------+
| 5486103a0640fd2ca3c1eb70 | core.local | stanley | succeeded | 2014-12-08T20:55:22.204000Z | 2014-12-08T20:55:25.792000Z |
| 548610540640fd2ca3c1eb71 | core.local | stanley | succeeded | 2014-12-08T20:55:48.021000Z | 2014-12-08T20:56:29.401000Z |
+--------------------------+------------+--------------+-----------+-----------------------------+-----------------------------+
```

After:

```
+--------------------------+------------+--------------+-----------+------------------------------+------------------------------+
| id | action | context.user | status | start_timestamp | end_timestamp |
+--------------------------+------------+--------------+-----------+------------------------------+------------------------------+
| 5486103a0640fd2ca3c1eb70 | core.local | stanley | succeeded | Mon, 08 Dec 2014 20:55:22 | Mon, 08 Dec 2014 20:55:25 |
| | | | | UTC | UTC |
| 548610540640fd2ca3c1eb71 | core.local | stanley | succeeded | Mon, 08 Dec 2014 20:55:48 | Mon, 08 Dec 2014 20:56:29 |
| | | | | UTC | UTC |
+--------------------------+------------+--------------+-----------+------
````