Remove test_build_egg. The test doesn't work and it's difficult to test _build_egg given the current interface.

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extra : amend_source : eb261716fc15148a101c059fb03c0f51b683c673

--HG--
extra : amend_source : d60530fbb3e3cc3455abae8e5100f85f697f3dac

Use a context manager instead of calling _test.run in multiple places. Alleviates need to warn about Exceptions

On Python 3.3+, `find_packages()` now considers any subdirectory of the
start directory that's not a regular package (i.e., that doesn't have an
`__init__.py`) to be a namespace package. Because this will often
include non-package directories, a new `include` argument has been added
to `find_packages()`.

`include` can make it easier to narrow which directories are considered
packages instead of having to specify numerous excludes. In
particular, it's an easy way to keep top-level, non-source directories
from being considered packages.

The other way this supports PEP 420 is by making sure `__pycache__`
directories are never added to the list of packages.

Refs issue #97