* snowflake errors
* added big query
* added to setup error messages, first test
* all big query testing added
* added snowflake test
* added syntax error
* added syntax errors to most used databases
* 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>
