Merge tag '3.1.0' into develop

3.1.0
Add failing test for issue #98
Test for the case that no doc_string is present as well
Modify isort to pass the new additional tests, and fix bug #98
Small tweak
Merge pull request #99 from timothycrosley/feature/fix-issue-98

Feature/fix issue 98
Bump version to 3.1.1
Merge branch 'release/3.1.1'