Check if database table "users" exists.
Merge pull request #14 from johnjohndoe/handle-missing-user-table

Check if database table "users" exists.
Describe how to import from folders and files.
Merge pull request #15 from johnjohndoe/describe-import-options

Describe how to import from folders and files.
Fix errors criticized by pep8.
Merge pull request #16 from johnjohndoe/fix-python-style-guide-errors

Fix errors criticized by pep8.