flake8 fixes

Signed-off-by: Kwpolska <kwpolska@gmail.com>
format() for command_import_wordpress

Signed-off-by: Kwpolska <kwpolska@gmail.com>
fixing a few missing )’s

Signed-off-by: Kwpolska <kwpolska@gmail.com>
moving flake8 installation to .travis.yml

Signed-off-by: Kwpolska <kwpolska@gmail.com>
Ading --exit-zero back.  Reason:

nikola/data/themes/default/messages/messages_zh-cn.py:2:41: E901 SyntaxError:
invalid syntax
nikola/plugins/compile_rest/pygments_code_block_directive.py:4:2: E901
SyntaxError: invalid syntax

Both are nonsense.

Signed-off-by: Kwpolska <kwpolska@gmail.com>
solve conflicts