Add SQL query to join student and student_attendance tables
Add SQL query to join student and student_attendance tables

+ Thanks @marimuraki for the help with joins
+ #47

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