commit subtest check_commit_default fail about autotest-docker

[luwensu]

IMO, One way to fix is pass docker_data_prepare_cmd in [docker_cli/commit]
into the sub case part and let the command in [docker_cli/commit/check_default_cmd]
redirect to stdout, i'll sent a patch to fix this tomorrow.

[cevich]

I didn't write this test and haven't looked deeply at the code in a long while. Normally I just re-write the test from scratch since sometimes that is faster than trying to read old/mouldy code. Anyway, thanks for the research into this, I'm glad you figured it out. Another idea might be to change the command to use tee instead of simple redirect. e.g. `"echo '%%s' | tee /var/i"```. Whatever way you think is best or most efficient is fine by me. Thanks again for looking into this.

[luwensu]

Thanks so much! It's more easier than my thought.I only did a quick fix to make the case pass first.
And i wonder how to update the document, since i found subtest.rst is in the list of .gitignore.
If it's okay to add it back, i'd like to push a patch to make up the document, not much, just delete one line about check_results_contain.

[cevich]

I see from #501 I think you figured it out. subtest.rst is automatically generated by parsing the main subtest module docstring and doing some magic with the corresponding ini file. Assuming you have python-docutils and python-sphinx installed, running make should build it for you. I thought I wrote some docs about this....hmmm, guess not, better add that to the list.

[cevich]

Docs link: http://docker-autotest.readthedocs.org/en/latest/#docker-cli-commit-subtest

(will rebuild based on #501 changes to master shortly)