fixes #75 one too many y-axis tick groups
fixes #75 one too many y-axis tick groups

bryceroney/Chartbuilder,ajam/Chartbuilder,valdobc/volt-teste,bryceroney/Chartbuilder,johnsonchandra/Chartbuilder,correctiv/Chartbuilder,defenseone/Chartbuilder,SCPR/Chartbuilder,Quartz/Chartbuilder,conversation/Chartbuilder,louisstow/Chartbuilder,zhangweiabc/Chartbuilder,SCPR/Chartbuilder,johnsonchandra/Chartbuilder,ajam/Chartbuilder,DistilledLtd/Chartbuilder,louisstow/Chartbuilder,nowthis/Chartbuilder,DistilledLtd/Chartbuilder,smartkarma/Chartbuilder,valdobc/volt-teste,correctiv/Chartbuilder,zhangweiabc/Chartbuilder,laurenancona/Chartbuilder,kway/Chartbuilder,Quartz/Chartbuilder,taylorhxu/Chartbuilder,NerdWallet/Chartbuilder,NerdWallet/Chartbuilder,bwareham/Chartbuilder2,nowthis/Chartbuilder,bwareham/Chartbuilder2,taylorhxu/Chartbuilder,ducroquet/Chartbuilder,defenseone/Chartbuilder,ducroquet/Chartbuilder,laurenancona/Chartbuilder,kway/Chartbuilder