support/testing: add new test for python-s3transfer

Many actual tests require network usage, so just import the module to
check that at least that part works.

Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

support/testing/tests/package/sample_python_s3transfer.py

@@ -0,0 +1 @@
+import s3transfer

support/testing/tests/package/test_python_s3transfer.py

@@ -0,0 +1,12 @@
+from tests.package.test_python import TestPythonPackageBase
+
+
+class TestPythonPy3S3transfer(TestPythonPackageBase):
+    __test__ = True
+    config = TestPythonPackageBase.config + \
+        """
+        BR2_PACKAGE_PYTHON3=y
+        BR2_PACKAGE_PYTHON_S3TRANSFER=y
+        """
+    sample_scripts = ["tests/package/sample_python_s3transfer.py"]
+    timeout = 10