Exception with shapes on charts with 2 Y axes

[KenCoder]

Repro here: http://codepen.io/KenCoder/pen/MeamNv. See console - plotly throws an "Uncaught TypeError: Cannot read property 'append' of undefined" when drawing. Removing second axis, removing layer: 'below' both make it go away.

[etpinard]

Confirmed. Thanks for the report.