Do not use a context manager with assertRaises

This is for python2.6 compatibility.

Author: Alex Schworer

test/test_zencoder.py

@@ -42,8 +42,11 @@ def test_set_base_url(self):
 
     def test_set_base_url_and_version_fails(self):
         os.environ['ZENCODER_API_KEY'] = 'abcd123'
-        with self.assertRaises(zencoder.core.ZencoderError):
-            zc = Zencoder(base_url='https://localhost:800/foo/', api_version='v3')
+
+        self.assertRaises(zencoder.core.ZencoderError,
+                          Zencoder,
+                          base_url='https://localhost:800/foo/',
+                          api_version='v3')
 
     def test_set_timeout(self):
         api_key = 'testapikey'