add explicit ordering of outputs and executions

[robinjoseph08]

What

Add explicit ordering of:

• job_execution_outputs on the executions show page
• executions on the jobs show page

  Why

This is because certain DBs (like postgres) doesn't guarantee an inherent ordering of queries unless it has been explicitly declared.

Notes

I removed :created_at => :desc, :started_at => :desc from the ordering of executions because these were sorting on the executions columns, but then we do a .find so the sorting was unnecessary.

[jamesrwhite]

Seems to do the trick, thanks! #174