fix flake8 errors
fix flake8 errors

Signed-off-by: Lovesh Harchandani <6bf7215c1b95516e7475a6bb01d5c0638c3b3fd8@gmail.com>

spivachuk/sovrin-node,spivachuk/sovrin-node,spivachuk/sovrin-node,spivachuk/sovrin-node