Disable zip_safe

Without zip disabled, setup.py install was installing SimpleITK as a
compressed egg. This prevented loading for the _SimpleITK.so library
resulting is the following error message when "import SimpleITK" was
executed:
>>> import SimpleITK
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File
  "/home/blowekamp/.virtualenvs/build-sitk/lib/python2.7/site-packages/SimpleITK-1.0.0-py2.7-linux-x86_64.egg/SimpleITK/__init__.py",
  line 1, in <module>
  File
  "/home/blowekamp/.virtualenvs/build-sitk/lib/python2.7/site-packages/SimpleITK-1.0.0-py2.7-linux-x86_64.egg/SimpleITK/SimpleITK.py",
  line 17, in <module>
  File
  "/home/blowekamp/.virtualenvs/build-sitk/lib/python2.7/site-packages/SimpleITK-1.0.0-py2.7-linux-x86_64.egg/SimpleITK/SimpleITK.py",
  line 16, in swig_import_helper
  File "/usr/lib64/python2.7/importlib/__init__.py", line 37, in
  import_module
    __import__(name)
ImportError: No module named _SimpleITK

Author: blowekamp

setup.py

@@ -46,5 +46,6 @@
     keywords='ITK InsightToolkit segmentation registration image',
     url=r'http://simpleitk.org/',
     install_requires=[],
-    setup_requires=['scikit-build>=0.5']
+    setup_requires=['scikit-build>=0.5'],
+    zip_safe=False
     )