fix N402 for nova-manage

fix N402 (docstrings should end in a period) for nova-manage

Change-Id: Ia07796117fb9fce6c098a58aa86a6b47c6f7eda0
fix N402 on tools/

fix N402 (single line docstrings should end in a period)

Change-Id: I2086dfb33a6efeb6ef6edc6a326182b6deda2527
Merge "fix N402 for nova-manage"
Merge "fix N402 on tools/"