Fix pylint3 errors about "deprecated-method".

Bug: 143197659
Test: # Change Python version to python3
      pylint3 internal/lib/gcompute_client.py
      pylint3 internal/lib/gcompute_client_test.py

Change-Id: If3bef631a33db7d20e071edd39c1b1512860aed1
diff --git a/internal/lib/gcompute_client_test.py b/internal/lib/gcompute_client_test.py
index 5f14f7e..d67c50b 100644
--- a/internal/lib/gcompute_client_test.py
+++ b/internal/lib/gcompute_client_test.py
@@ -20,6 +20,7 @@
 import os
 
 import unittest
+import six
 import mock
 
 # pylint: disable=import-error
@@ -150,11 +151,12 @@
         self._SetupMocksForGetOperationStatus(
             {"error": {"errors": ["error1", "error2"]}},
             gcompute_client.OperationScope.GLOBAL)
-        self.assertRaisesRegexp(errors.DriverError,
-                                "Get operation state failed.*error1.*error2",
-                                self.compute_client._GetOperationStatus,
-                                {"name": self.OPERATION_NAME},
-                                gcompute_client.OperationScope.GLOBAL)
+        six.assertRaisesRegex(self,
+                              errors.DriverError,
+                              "Get operation state failed.*error1.*error2",
+                              self.compute_client._GetOperationStatus,
+                              {"name": self.OPERATION_NAME},
+                              gcompute_client.OperationScope.GLOBAL)
 
     @mock.patch.object(errors, "GceOperationTimeoutError")
     @mock.patch.object(utils, "PollAndWait")
@@ -340,7 +342,8 @@
                 "source": GS_IMAGE_SOURCE_URI,
             },
         }
-        self.assertRaisesRegexp(
+        six.assertRaisesRegex(
+            self,
             errors.DriverError,
             "Expected fake error",
             self.compute_client.CreateImage,
@@ -1082,7 +1085,8 @@
                 instance=self.INSTANCE, zone=self.ZONE)
             self.assertEqual(result, "fake contents")
         else:
-            self.assertRaisesRegexp(
+            six.assertRaisesRegex(
+                self,
                 errors.DriverError,
                 "Malformed response.*",
                 self.compute_client.GetSerialPortOutput,
@@ -1199,10 +1203,11 @@
         """Test the rsa key path not exists."""
         fake_ssh_rsa_path = "/path/to/test_rsa.pub"
         self.Patch(os.path, "exists", return_value=False)
-        self.assertRaisesRegexp(errors.DriverError,
-                                "RSA file %s does not exist." % fake_ssh_rsa_path,
-                                gcompute_client.GetRsaKey,
-                                ssh_rsa_path=fake_ssh_rsa_path)
+        six.assertRaisesRegex(self,
+                              errors.DriverError,
+                              "RSA file %s does not exist." % fake_ssh_rsa_path,
+                              gcompute_client.GetRsaKey,
+                              ssh_rsa_path=fake_ssh_rsa_path)
 
     def testGetRsaKey(self):
         """Test get the rsa key."""