bash commands do not work with python-3.5

[mmmaat]

For some unknown and unexpected reason, the bash commands fail when wordseg runs with python-3.5 (see the test/test_bash_python.py test, see also here for a test report).

The obtained results in bash are inconsistent with those from a pure python call. Furthermore, they seems to be random!!

I'm suspecting prepare.py:main(), but no proof yet.

[mmmaat]

Fixed by commit 8560395.