Use use ssl_context or don't but don't mix (#714)

* Use original SSL process and add SSLContext

Not going to deprecate and replace with SSLContext.
But instead give option for using SSLContext next to the original way of
handling SSL.

test_elasticsearch/test_connection.py

@@ -10,11 +10,28 @@ from elasticsearch.exceptions import TransportError, ConflictError, RequestError
 from elasticsearch.connection import RequestsHttpConnection, \
     Urllib3HttpConnection
 from elasticsearch.exceptions import ImproperlyConfigured
-from elasticsearch.connection.http_urllib3 import create_ssl_context
 from .test_cases import TestCase, SkipTest
 
 
 class TestUrllib3Connection(TestCase):
+    def test_ssl_context(self):
+        try:
+            context = ssl.create_default_context()
+        except AttributeError:
+            # if create_default_context raises an AttributeError Exception
+            # it means SSLContext is not available for that version of python
+            # and we should skip this test.
+            raise SkipTest(
+                "Test test_ssl_context is skipped cause SSLContext is not available for this version of ptyhon")
+
+        con = Urllib3HttpConnection(use_ssl=True, ssl_context=context)
+        self.assertEqual(len(con.pool.conn_kw.keys()), 1)
+        self.assertIsInstance(
+            con.pool.conn_kw['ssl_context'],
+            ssl.SSLContext
+        )
+        self.assertTrue(con.use_ssl)
+
     def test_timeout_set(self):
         con = Urllib3HttpConnection(timeout=42)
         self.assertEquals(42, con.timeout)
@@ -45,12 +62,6 @@ class TestUrllib3Connection(TestCase):
             'connection': 'keep-alive'}, con.headers)
 
     def test_uses_https_if_verify_certs_is_off(self):
-        if (
-            sys.version_info >= (3,0) and sys.version_info <= (3,4)
-            ) or (
-            sys.version_info >= (2,6) and sys.version_info <= (2,7)
-        ):
-            raise SkipTest("SSL Context not supported in this version of python")
         with warnings.catch_warnings(record=True) as w:
             con = Urllib3HttpConnection(use_ssl=True, verify_certs=False)
             self.assertEquals(1, len(w))
@@ -62,14 +73,6 @@ class TestUrllib3Connection(TestCase):
         con = Urllib3HttpConnection()
         self.assertIsInstance(con.pool, urllib3.HTTPConnectionPool)
 
-    def test_ssl_context_and_depreicated_values(self):
-        try:
-            ctx = create_ssl_context()
-        except AttributeError:
-            raise SkipTest("SSL Context not supported in this version of python")
-        self.assertRaises(ImproperlyConfigured, Urllib3HttpConnection, ssl_context=ctx, ca_certs="/some/path/to/cert.crt")
-        self.assertRaises(ImproperlyConfigured, Urllib3HttpConnection, ssl_context=ctx, ssl_version=ssl.PROTOCOL_SSLv23)
-
 class TestRequestsConnection(TestCase):
     def _get_mock_connection(self, connection_params={}, status_code=200, response_body='{}'):
         con = RequestsHttpConnection(**connection_params)