Set zip_safe=False in setup.py

Without this explicit setting, setuptools examines our source code to
deduce the value.  This change make installation more efficient,
reduces the message spew during installation, and
does not change the choice made by setuptools.
----Release Notes----
[]
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=118980930

Author: gildea

setup.py

@@ -115,6 +115,7 @@ def get_download_url():
     setup_requires=['nose>=1.0'],
     install_requires=REQUIRED_PACKAGES,
     test_suite='nose.collector',
+    zip_safe=False,
     # PyPI package information.
     classifiers=[
         'Intended Audience :: End Users/Desktop',