fix safe file handling in unit tests

[tomkralidis]

Description

Unit tests in a Python 3 environment yield ResourceWarning warnings like:

/home/travis/build/geopython/pywps/tests/test_inout.py:64: ResourceWarning: unclosed file <_io.FileIO name='/tmp/tmpwbpvbq0c' mode='rb'>

Environment

• operating system: Ubuntu
• Python version: 3.4
• PyWPS version: master
• source/distribution
  • [x] git clone
  • [ ] Debian
  • [ ] PyPI
  • [ ] zip/tar.gz
  • [ ] other (please specify):
• web server
  • [ ] Apache/mod_wsgi
  • [ ] CGI
  • [x] other (please specify): unit test runner

    Steps to Reproduce

# in a Python 3 virtualenv
python -m unittest tests

Additional Information

Initial discussion in #106.

Example can be found in current travis builds: https://travis-ci.org/geopython/pywps/jobs/111190874#L360

[mishravikas]

Can I take this bug?

[tomkralidis]

Sounds good @mishravikas!

[jachym]

@mishravikas go for it, but I'm not sure it's easy to be fixed. Have a look in it and in case, you are not sure how to approach, just move on with your tasks

[ldesousa]

Line 160 in inout/basic.py, in the method get_stream() save a reference to the file object. CLose this file object after the handler is called - Process class, _run_process() method.

[jachym]

https://docs.python.org/3/reference/datamodel.html del object destroyer should do it

[jachym]

175 fixes this