Add missing imports

Author: itziakos

traits/api.py

@@ -78,6 +78,7 @@
     Module,
     Python,
     ReadOnly,
+    TypedReadOnly,
     Disallow,
     Constant,
     Delegate,

traits/tests/test_typed_read_only.py

@@ -14,6 +14,12 @@
 #  Date:   05/24/2019
 #
 # ------------------------------------------------------------------------------
+import unittest
+
+
+from traits.api import (
+    HasStrictTraits, Int, List, TraitError, TypedReadOnly, Undefined)
+
 
 class Dummy(HasStrictTraits):
 
@@ -35,7 +41,6 @@ def _value_2_changed(self, old, new):
         self.events_2.append((old, new))
 
 
-
 class TestTypedReadOnly(unittest.TestCase):
 
     def test_initialization(self):