Add integration test settings and tests for utils

[karenc]

• Add pep8 to travis
• Add integration tests with test packages
• Add test for utils.get_settings_from_config
• Add test for utils.with_cursor

• Fix dbmigrator generate migrations directory lookup

  Traceback (most recent call last):
  File "./bin/dbmigrator", line 9, in <module>
  load_entry_point('db-migrator==0.1.1', 'console_scripts', 'dbmigrator')()
  File "/home/karen/db-migrator/dbmigrator/cli.py", line 86, in main
  return args['cmmd'](**args)
  File "/home/karen/db-migrator/dbmigrator/commands/generate.py", line 25, in cli_comm
  path = os.path.join(directory, filename)
  File "/home/karen/db-migrator/lib/python3.4/posixpath.py", line 82, in join
  elif not path or path.endswith(sep):
  AttributeError: 'list' object has no attribute 'endswith'

• Make dbmigrator generate generate pep8 compliant code
• Add test for utils.import_migration
• Add test for utils.get_migrations
• Add test for utils.get_pending_migrations
• Add test for utils.run_migration
• Add test for utils.rollback_migration
• Add test for utils.timestamp