Improve README: introductory explanation and examples of use.
Add 'Troubleshooting' section with details of using --debug option.
Add a note about required configuration values.
Add a link to the source for DrupalTestUser class.
Add a constant for email domain to use for test user accounts.
Provide a more accurate description of (currently) required configuration.
Add getRootUser() method to return a representation of the user with uid 1; add instructions to README.
Use a JSON response from Drush to check if a user doesn't exist instead of an error message.
First attempt at CLI for creating/deleting test users.