* Specify engine for excel files
* Add test for the chagne related to pyxlsb
* Update changelog and bump connector version
* Update PR link and number
* Update spec to include 'excel_binary' option, formatted files
* Update spec for source-file-secure to match changes made in source-file spec
* Added inital test setup for client.py, added WIP tests for source.py
* Add tests for storage scheme and started tests for _open() method
* Unittest coverage increased to 90
* Small refactoring
Co-authored-by: Serhii Lazebnyi <53845333+lazebnyi@users.noreply.github.com>
Co-authored-by: Serhii Lazebnyi <serhii.lazebnyi@globallogic.com>