Add two tests demonstrating that requires.txt generation is deterministic. Ref #458.

setuptools/tests/test_egg_info.py

@@ -230,6 +230,20 @@ class TestEggInfo(object):
         #
         # expected contents of requires.txt
 
+        '''
+        install_requires_deterministic
+
+        install_requires=["fake-factory==0.5.2", "pytz"]
+
+        [options]
+        install_requires =
+            fake-factory==0.5.2
+            pytz
+
+        fake-factory==0.5.2
+        pytz
+        ''',
+
         '''
         install_requires_with_marker