Only show 'System' and 'Admin' roles on Admin Dashboard

* Previously, all of "Private Program", "Auditor" and "* Implied" roles
  were also shown and editable/deletable.
Merge pull request #634 from reciprocity/hotfix/fix-admin-page-roles-query

Only show 'System' and 'Admin' roles on Admin Dashboard
Bump to Version S16.1
More fixes for Admin Roles widget

* Show "Private Program" roles also
* Ensure both "System" and "Admin" roles are non-editable
Merge pull request #635 from reciprocity/hotfix/fix-admin-page-roles-query

Version bump; more Admin Roles fixes
Change to `datetime` attributes to `date`

* Due to the migration in b37ef4e404
Merge pull request #639 from reciprocity/hotfix/fix-audit-datetime-dates

Change to `datetime` attributes to `date`
Add `due_on` value to auto-generated Requests
Merge pull request #640 from reciprocity/hotfix/fix-request-autogeneration

Add `due_on` value to auto-generated Requests
Bump version to 16.2
Merge pull request #641 from reciprocity/hotfix/bump-version

Bump version to 16.2
Merge branch 'release/0.9a16' into develop
Bump version to s17