Send summary email reports

[nharper]

The report should include a list of members with number of absences, sorted by the number of absences (descending).

[davesw]

example of absence report in Excel.xlsx

Ok you don't need to generate an actual excel spread sheet. I just created the example in excel so I could put comments on each field. the example attached has three styles of rows: Ideal, Less Ideal, and Minimal.

[nharper]

Including email address should be really easy to do. I'm probably going to do the Less Ideal version for now, as the Ideal Row requires loading the RawAttendanceRecords (which have the timestamps) in addition to the AttendanceRecords. When I work on #26 I can come back to adding the timestamps.

Do you just want the total absence count, or do you also want it broken out by required ("Monday") rehearsals and optional/extra/make-up/pick-up rehearsals? How should presences and absences for optional rehearsals be handled?