2d quiver plots aren't showing arrows

[jackparmer]

Here's the code

u = cos(x)._y;
v = sin(x)._y;

figure
quiver(x,y,u,v)
fig2plotly()```

Here's the result

![image](https://cloud.githubusercontent.com/assets/1865834/8791575/9964391a-2f2a-11e5-85f2-5b435b184109.png)
https://plot.ly/~jackp/9543

This is the vanilla example in the MATLAB docs:
http://www.mathworks.com/help/matlab/ref/quiver.html

Running this on the 2014b version:
![image](https://cloud.githubusercontent.com/assets/1865834/8791570/8e7d636e-2f2a-11e5-8310-936415a2a3cb.png)