Bug fixes in zc.buildout.testing
================================

Logging handler which did not get deleted
-----------------------------------------

The buildout testing set up runs a buildout which adds a
``logging.StreamHandler`` to the root logger. But tear down did not
remove it. This can disturb other tests of packages reusing
zc.buildout.testing.

The handers before calling set up are:

    >>> import logging
    >>> len(logging.getLogger().handlers)
    1
    >>> logging.getLogger().handlers # doctest: +ELLIPSIS
    [<zope...testrunner.logsupport.NullHandler instance at ...>]

After calling it, a ``logging.StreamHandler`` was added:

    >>> import zc.buildout.testing
    >>> import doctest
    >>> test = doctest.DocTestParser().get_doctest(
    ...     '>>> x', {}, 'foo', 'foo.py', 0)
    >>> zc.buildout.testing.buildoutSetUp(test)
    >>> len(logging.getLogger().handlers)
    2
    >>> logging.getLogger().handlers # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
    [<zope...testrunner.logsupport.NullHandler instance at ...>,
     <logging.StreamHandler instance at ...>]

But tear down removes the new logging handler:

    >>> zc.buildout.testing.buildoutTearDown(test)
    >>> len(logging.getLogger().handlers)
    1
    >>> logging.getLogger().handlers # doctest: +ELLIPSIS
    [<zope...testrunner.logsupport.NullHandler instance at ...>]
