Stop VictoryAnimation from creating NaNs and passing them down as props
Stop VictoryAnimation from creating NaNs and passing them down as props

See comment! `d3.interpolate` does not support null or undefined values,
and this was causing VictoryAnimation to send NaN-valued props.

/cc @boygirl @colinmegill

FormidableLabs/victory-animation,FormidableLabs/victory-core,FormidableLabs/victory-animation,FormidableLabs/victory-core