v2.0 Checklist

[jdevries3133]

• make grader.graders generalizable. Create a base Grader class which defines
  the abstract grading framework
• remove IterCSV, replace with csv.DictReader
• add tests for google classroom module #13
• add tests for google client wrapper #12
• remove sis_proxy from teacherhelper.grader. It is not needed outside
  the context of the term 2 project
• move the tests in teacherhelper.test into teacherhelper.sis.tests.do some copy-pasting so that the test for the deprecated teacherhelper.Helperinterface remains #11
  do some copy-pasting so that the test for the deprecated teacherhelper.Helper
  interface remains
• move DocWriter into a separate module from grader. Add template
  replacement targets to add_page so that the DocWriter class can be
  concrete
• document DocWriter

[jdevries3133]

Remaining items will be left for 2.1.0. I added warnings in the docs about untested code in the google classroom module, and teacherhelper.test does exercise teacherhelper.sis, it just does so through the old interface.

[jdevries3133]

closing because google module tests were spun off as separate issues for a later time