make check command tests run nikola.main.main()

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
flake8

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
fix #908

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>