Remove setuptools-git from setup.py.

Put it in test-requires so it's there when we build a tarball.
Change-Id: I8a5adec74beeb397e71e17030338a8051fe6fb0b
Reviewed-on: https://review.openstack.org/19885
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins

setup.py

@@ -34,7 +34,6 @@ setuptools.setup(
     include_package_data=True,
     cmdclass=setup.get_cmdclass(),
     install_requires=requires,
-    setup_requires=['setuptools_git>=0.4'],
     dependency_links=depend_links,
     zip_safe=False,
     classifiers=[

tools/test-requires

@@ -1 +1,2 @@
 sphinx
+setuptools_git>=0.4