Use six to manage unicode strings in tests

setup.py

@@ -50,5 +50,6 @@
     ],
     install_requires=[
         'setuptools >= 0.6b1',
+        'six >= 1.10'
     ]
 )

voluptuous/tests/tests.py

@@ -560,11 +560,8 @@ def fn(arg):
 
 def test_unicode_key_is_converted_to_utf8_when_in_marker():
     """Verify that when using unicode key the 'u' prefix is not thrown in the exception"""
-    import sys
-    if sys.version_info >= (3,):
-        schema = Schema({Required('q'): 1})
-    else:
-        schema = Schema({Required(u'q'): 1})
+    import six
+    schema = Schema({Required(six.u('q')): 1})
     # Can't use nose's raises (because we need to access the raised
     # exception, nor assert_raises which fails with Python 2.6.9.
     try:
@@ -574,13 +571,9 @@ def test_unicode_key_is_converted_to_utf8_when_in_marker():
 
 
 def test_unicode_key_is_converted_to_utf8_when_plain_text():
-    import sys
-    if sys.version_info >= (3,):
-        schema = Schema({'q': int})
-        key = 'q'
-    else:
-        schema = Schema({u'q': int})
-        key = u'q'
+    import six
+    key = six.u('q')
+    schema = Schema({key: int})
     # Can't use nose's raises (because we need to access the raised
     # exception, nor assert_raises which fails with Python 2.6.9.
     try:
@@ -590,10 +583,7 @@ def test_unicode_key_is_converted_to_utf8_when_plain_text():
 
 
 def test_to_utf8_py2():
-    import sys
+    import six
     from voluptuous.encoding import to_utf8_py2
-    if sys.version_info >= (3,):
-        s = 'hello'
-    else:
-        s = u'hello'
+    s = six.u('hello')
     assert_true(isinstance(to_utf8_py2(s), str))