Fix for NaN/Inf line tests
Fix for NaN/Inf line tests

Use lines that do not contain single points when rendered so that
tests are not affected by fix for d3 #2061.

e-koch/mpld3,e-koch/mpld3,jakevdp/mpld3,etgalloway/mpld3,kdheepak89/mpld3,kdheepak89/mpld3,etgalloway/mpld3,jakevdp/mpld3,mpld3/mpld3,mpld3/mpld3