Run Structure and Behavior tests in Python 3 (#22)

Fix #21.

Author: stasm

.travis.yml

@@ -3,6 +3,7 @@ language: python
 python:
   - "2.7"
   - "3.5"
+  - "3.6"
   - "nightly"
 install: pip install tox-travis
 script: tox

setup.py

@@ -20,5 +20,6 @@
       packages=['fluent', 'fluent.syntax', 'fluent.migrate'],
       package_data={
           'fluent.migrate': ['cldr_data/*']
-      }
-      )
+      },
+      tests_require=['six']
+)

tests/syntax/test_behavior.py

@@ -1,4 +1,6 @@
 from __future__ import unicode_literals
+from six import with_metaclass
+
 import os
 import re
 import sys
@@ -99,7 +101,5 @@ def test(self):
         return type.__new__(mcs, name, bases, attrs)
 
 
-class TestBehavior(unittest.TestCase):
+class TestBehavior(with_metaclass(TestBehaviorMeta, unittest.TestCase)):
     maxDiff = None
-
-    __metaclass__ = TestBehaviorMeta

tests/syntax/test_structure.py

@@ -1,4 +1,6 @@
 from __future__ import unicode_literals
+from six import with_metaclass
+
 import os
 import sys
 import json
@@ -50,7 +52,5 @@ def test(self):
         return type.__new__(mcs, name, bases, attrs)
 
 
-class TestStructure(unittest.TestCase):
+class TestStructure(with_metaclass(TestStructureMeta, unittest.TestCase)):
     maxDiff = None
-
-    __metaclass__ = TestStructureMeta

tox.ini

@@ -1,11 +1,12 @@
 [tox]
-envlist = py27, py27-cl, py36
+envlist = py27, py27-cl, py35, py36
 skipsdist=True
 
 [testenv]
 setenv =
     PYTHONPATH = {toxinidir}
 deps =
+    six
     cl: compare-locales
 
 commands=python -m unittest discover