fix: Use unittest.mock if available

The `mock` module is deprecated in recent Python versions.

Signed-off-by: Major Hayden <[email protected]>

tests/system/requests/test_upload.py

@@ -20,7 +20,10 @@
 import urllib.parse
 
 import pytest  # type: ignore
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 from google.resumable_media import common
 from google import resumable_media

tests/unit/requests/test__helpers.py

@@ -14,7 +14,10 @@
 
 import http.client
 
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 import pytest  # type: ignore
 
 import requests.exceptions

tests/unit/requests/test_download.py

@@ -15,7 +15,10 @@
 import http.client
 import io
 
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 import pytest  # type: ignore
 
 from google.resumable_media import common

tests/unit/requests/test_upload.py

@@ -16,7 +16,10 @@
 import io
 import json
 
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 import google.resumable_media.requests.upload as upload_mod
 

tests/unit/test__helpers.py

@@ -17,7 +17,10 @@
 import hashlib
 import http.client
 
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 import pytest  # type: ignore
 
 from google.resumable_media import _helpers

tests/unit/test__upload.py

@@ -16,7 +16,10 @@
 import io
 import sys
 
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 import pytest  # type: ignore
 
 from google.resumable_media import _helpers

tests/unit/test_common.py

@@ -12,7 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 import pytest  # type: ignore
 
 from google.resumable_media import common