15a9f53f0001f135bc00589e00f269b4bb8297d9

The check_output method is only available from Python 2.7, so a wrapper method was introduced for compatibility with 2.6. The ZipFile class does not include context manager support in Python 2.6, so the file download code was written to explicitly open and close the zip files. Since Buck itself now requires at least Python 2.7, these workarounds are no longer necessary. Remove them. Also, tidy up a few minor PEP-8 coding style violations in the modified files. Change-Id: I9a1b25ddf7494e25ccadeaed0c1d85cd1ce2fd09
Description
RETIRED, Gerrit as used by OpenStack