Fix result handling of ec2_run_instance

[manasdk]

Fix to align with changes to AWS pack StackStorm/st2contrib#393

[Kami]

Cool.

It would also be a good idea to merge the branch from #126 (destroy_vm_changes) into yours or vice-versa so everything is self contained and easy to test.

[Kami]

I will merge my PR into this one.

[manasdk]

@Kami Your call on how to merge this branch etc.

[Kami]

I'm testing those changes and it doesn't look like destroy_vm works correctly - it doesn't seem to delete an instance if one already exists.

In any case, I will let @m4dcoder test and investigate this when he's back since he has more context on the whole Mistral workflow...

[Kami]

Also, we need to be careful when testing those changes since it would be really bad if the action deleted wrong instance(s).

[Kami]

OK, so the good news.

I tested those + aws pack changes locally on the build server and it looks like they work - all the workroom tests pass. There might still be some other tests / workflows affected, but we should fix those when they pop up.

I will go ahead, merge both of those changes and deploy them to st2build002.

"destroy_vm" still doesn't look like it works as it should, but I'll leave this to @m4dcoder when he's back.