quantopian/zipline — pull request #341 by twiecki (2014-06-02 13:53:04+00:00)
Title: STY: Remove warning when ordering zero shares.

Many algorithms that use the new order methods like order_target()
will legitimately try to order 0 shares many times. The printed
warning at every turn is quite annoying and too verbose. We do not
display it on Quantopian either so I'm removing it here as well.