`test_curses_application` hangs occasionally

[alex-eg]

make view_cov just hangs at

xoinvader/tests/test_application.py::test_curses_application 

line.
Happened 4 times to me.

[alex-eg]

^C trace:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! KeyboardInterrupt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
to show a full traceback on KeyboardInterrupt use --fulltrace
/home/alex/dev/xoinvader/.venv/lib/python3.5/site-packages/tornado/ioloop.py:862: KeyboardInterrupt

[alex-eg]

Just happened 4 more times. Ugh.

[pkulev]

wow, never caught this. Maybe I am working with loop wrong at some actions...