Django-development-fabfile

- drop_db task also drops the database role now

- Added creation of DB role to create_db task.

- Added TEST_SETTINGS_PATH setting to fabfile_settings.py
This allows you to use our fab test task even if your settings have a
different path than `myproject.settings.test_settings`

- Added check_coverage and check tasks.

- Added fab tasks to import / export / upload / download postgres databases

- Fixed bad DB_NAME in `create_db` task.