Return package version as listed in `__version__` in `init.py`.

def get_version(package):
    """
    Return package version as listed in `__version__` in `init.py`.
    """
    init_py = codecs.open(os.path.join(package, '__init__.py'), encoding='utf-8').read()
    return re.search("^__version__ = ['\"]([^'\"]+)['\"]", init_py, re.MULTILINE).group(1)