Stop testing EOL Python 2.6 and 3.3 (#62)

Python 2.6 and 3.3 are EOL. They are no longer receiving bug fixes,
including for security issues. Python 2.6 went EOL on 2013-10-29 and
Python 3.3 went EOL on 2017-09-29. For details, see:

https://devguide.python.org/#status-of-python-branches

For additional discussion on why project maintainers may wish to drop
Python 2.6 support, please see:

https://snarky.ca/stop-using-python-2-6/
http://www.curiousefficiency.org/posts/2015/04/stop-supporting-python26.html

Reduces testing resources.

.travis.yml

@@ -1,8 +1,6 @@
 language: python
 python:
-  - "2.6"
   - "2.7"
-  - "3.3"
   - "3.4"
   - "3.5"
   - "3.6"
@@ -12,4 +10,3 @@ install:
   - pip install .
 script:
   - python setup.py test
-

README.rst

@@ -55,7 +55,7 @@ Alternatively, you can install the package using the bundled setup script:
 
     $ python setup.py install
 
-This library works with Python 2.6 or later, and Python 3.3 or later.
+This library works with Python 2.7 and Python 3.4 or later.
 
 
 Usage
@@ -195,7 +195,7 @@ in computing the table data. For example, ``idna-data --version 9.0.0 make-libda
 will generate library data against Unicode 9.0.0.
 
 Note that this script requires Python 3, but all generated library data will work
-in Python 2.6+.
+in Python 2.7.
 
 
 Testing

setup.py

@@ -13,8 +13,8 @@
 def main():
 
     python_version = sys.version_info[:2]
-    if python_version < (2,6):
-        raise SystemExit("Sorry, Python 2.6 or newer required")
+    if python_version < (2,7):
+        raise SystemExit("Sorry, Python 2.7 or newer required")
 
     package_data = {}
     exec(open('idna/package_data.py').read(), package_data)
@@ -36,17 +36,17 @@ def main():
             'License :: OSI Approved :: BSD License',
             'Operating System :: OS Independent',
             'Programming Language :: Python',
-            'Programming Language :: Python :: 2.6',
+            'Programming Language :: Python :: 2',
             'Programming Language :: Python :: 2.7',
             'Programming Language :: Python :: 3',
-            'Programming Language :: Python :: 3.3',
             'Programming Language :: Python :: 3.4',
             'Programming Language :: Python :: 3.5',
             'Programming Language :: Python :: 3.6',
             'Topic :: Internet :: Name Service (DNS)',
             'Topic :: Software Development :: Libraries :: Python Modules',
             'Topic :: Utilities',
         ],
+        'python_requires': '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
         'test_suite': 'tests',
     }
 

tests/test_idna.py

@@ -1,17 +1,13 @@
 #!/usr/bin/env python
 
 import unittest
-import sys
 
 import idna
 
 
 class IDNATests(unittest.TestCase):
 
     def setUp(self):
-
-        self.python_version = sys.version_info[:2]
-
         self.tld_strings = [
             [u'\u6d4b\u8bd5', b'xn--0zwm56d'],
             [u'\u092a\u0930\u0940\u0915\u094d\u0937\u093e', b'xn--11b5bs3a9aj6g'],
@@ -243,9 +239,8 @@ def test_encode(self):
         self.assertEqual(idna.encode('abc.abc'), b'abc.abc')
         self.assertEqual(idna.encode('xn--zckzah.abc'), b'xn--zckzah.abc')
         self.assertEqual(idna.encode(u'\u30c6\u30b9\u30c8.abc'), b'xn--zckzah.abc')
-        if self.python_version != (2, 6):
-            self.assertEqual(idna.encode(u'\u0521\u0525\u0523-\u0523\u0523-----\u0521\u0523\u0523\u0523.aa'),
-                                     b'xn---------90gglbagaar.aa')
+        self.assertEqual(idna.encode(u'\u0521\u0525\u0523-\u0523\u0523-----\u0521\u0523\u0523\u0523.aa'),
+                         b'xn---------90gglbagaar.aa')
         self.assertRaises(idna.IDNAError, idna.encode,
                           u'\u0521\u0524\u0523-\u0523\u0523-----\u0521\u0523\u0523\u0523.aa', uts46=False)
         self.assertEqual(idna.encode('a'*63), b'a'*63)
@@ -258,9 +253,8 @@ def test_decode(self):
         self.assertEqual(idna.decode(u'\u30c6\u30b9\u30c8.\u30c6\u30b9\u30c8'),
                          u'\u30c6\u30b9\u30c8.\u30c6\u30b9\u30c8')
         self.assertEqual(idna.decode('abc.abc'), u'abc.abc')
-        if self.python_version != (2, 6):
-            self.assertEqual(idna.decode('xn---------90gglbagaar.aa'),
-                                     u'\u0521\u0525\u0523-\u0523\u0523-----\u0521\u0523\u0523\u0523.aa')
+        self.assertEqual(idna.decode('xn---------90gglbagaar.aa'),
+                         u'\u0521\u0525\u0523-\u0523\u0523-----\u0521\u0523\u0523\u0523.aa')
         self.assertRaises(idna.IDNAError, idna.decode, 'XN---------90GGLBAGAAC.AA')
         self.assertRaises(idna.IDNAError, idna.decode, 'xn---------90gglbagaac.aa')