Boxplot points not drawn in some cases

[Jeff-Clark]

See https://jsfiddle.net/cf4j5vxz/

Traced it into code line
newJitter = trace.jitter * 2 / maxJitterFactor;
maxJitterFactor is zero in some cases when lots of data points are zero.

[etpinard]

Bug confirmed. Thanks for reporting.

Looks like you found the root of the problem. This would a great opportunity for a first contributor to make his/her first PR.

[alexcjohnson]

closed by #915