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>

tests/load_examples_test.py

@@ -17,11 +17,7 @@
 from .base_tests import SupersetTestCase
 
 
-class SupersetDataFrameTestCase(SupersetTestCase):
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.examples = None
-
+class TestSupersetDataFrame(SupersetTestCase):
     def setUp(self) -> None:
         # Late importing here as we need an app context to be pushed...
         from superset import examples