0.2.8 Version Bump

Clear Submission

Remove a submission from ORA by cancelling it to remove from grading
pools, then passing through to submissions.

Profiling changes and data

Made a few small optimizations to acceptance tests, added ability to profile
tests with an environment var, and updated .gitignore to ignore files
generated when running acceptance tests locally.

Update to latest nose, bok-choy.

more test info

Minor a11y fixes.

TNL-4112

Update bok choy tests to have unique emails.

Declare all packages.

edx-platform no longer using "-e" when installing

Bump version to 0.2.7.

Increase the final comment textarea size

Change how staff tool tabs work.

Always calculate peer median

The comment textarea size has been increase to 1000 and the final
comment size is smaller now. Increases to 1000 to match the comment
textarea size. Reference: https://github.com/edx/edx-ora2/pull/811

TNL-4021

TNL-4002

Previously, we were only showing the "more assessments needed" message
when there were 0 assessments, but we also need to show it when there are
0 < n < must_be_graded_by assessments for the user, to prevent a blank
area on the grade report. We also supress feedback comments from peers in
this case.

Required some refactoring of the base test case

Take care to avoid default behavior of get_workflow_info.

TNL-4060

Scope the submission response to the correct form elements.

Christina/fix pep8

Weekly Release

Add feedback text to self assessments

Also includes fix to default text, and removal of a seemingly unused,
hardcoded 'estimated_time' context variable. A11y test uncommented.