Catch repo exceptions
Fix trailing whitespace
Merge pull request #1900 from kubasub/rspec-tests

Rspec tests
Update summaries table for flexible criteria
Fix whitespace
Fix invalid submission bug #1859, #1897
Merge pull request #1895 from david-yz-liu/submissions-table

Catch repo exceptions
Merge pull request #1901 from david-yz-liu/summaries-update

Update summaries table for flexible criteria
Merge pull request #1902 from oneohtrix/master

Fix #1897
refactoring: grouped association tests and validation tests
created rspec tests for Assignment#section_due_date
created/refactored tests for Assignment#past_due_date?
refactor: removed brackets around eq matcher
created Assignment#latest_due_date; reworded examples to be more explicit
restructured/added additional testcases for Assignment#section_due_date
rspec tests for Assignment#section_past_due_date (and moved #latest_due_date method)
removed migrated tests
removed migrated test
rewrote Assignment#what_past_due_date rspec tests
refactored matchers that should be strictly boolean