feat: Switch from nosetest to pytest (#10177)

* Switch from nosetest to pytest

Fix schedule tests

Collect pytest coverage

Move pytest config into pytest.ini

Move cov to the pytest.ini

* Append coverage for the 2nd run

* Add coverage to all commands

* Coverage only for tests

* Get coverage from 1 place

* Rename classes to be  pytest compatible

* Test coverage for examples and tests

* Max diff to -1

* Explain how to run pytest for the whole project

* Do not append code coverage for the main run

* Do not run coverage on examples

Co-authored-by: bogdan kyryliuk <bogdankyryliuk@dropbox.com>

pytest.ini

@@ -0,0 +1,21 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+[pytest]
+addopts = -ra -q
+testpaths =
+    tests
+python_files = *_test.py test_*.py *_tests.py