Added unit tests for hooks module

tests/test_hooks.py

@@ -0,0 +1,22 @@
+# coding: utf-8
+import pytest
+
+from requests import hooks
+
+
+def hook(value):
+    return value[1:]
+
+
+@pytest.mark.parametrize(
+    'hooks_list, result', (
+        (hook, 'ata'),
+        ([hook, lambda x: None, hook], 'ta'),
+    )
+)
+def test_hooks(hooks_list, result):
+    assert hooks.dispatch_hook('response', {'response': hooks_list}, 'Data') == result
+
+
+def test_default_hooks():
+    assert hooks.default_hooks() == {'response': []}