Make STAR charts nice and smooth
Make STAR charts nice and smooth

+ When a STAR result date has reading results but not math (or vice versa), drop the missing result from chart
+ This will make our charts smooth and not all disconnected
+ #160

hunterowens/somerville-teacher-tool,jamestyack/somerville-teacher-tool,jhilde/studentinsights,jamestyack/somerville-teacher-tool,erose/studentinsights,codeforamerica/somerville-teacher-tool,codeforamerica/somerville-teacher-tool,hunterowens/somerville-teacher-tool,jhilde/studentinsights,erose/studentinsights,jamestyack/somerville-teacher-tool,jhilde/studentinsights,jhilde/studentinsights,codeforamerica/somerville-teacher-tool,hunterowens/somerville-teacher-tool,studentinsights/studentinsights,studentinsights/studentinsights,erose/studentinsights,erose/studentinsights,codeforamerica/somerville-teacher-tool,studentinsights/studentinsights,studentinsights/studentinsights