Adding integration tests

[i-wagner]

Description

This PR implements a basic framework for integration tests that can be run against snowflake-manager

Changes

• Adding fixture for Snowflake connection/cursor
• Updating GitHub workflow so that it pulls env variables, required for connecting to Snowflake
• Adding integration tests for ddl and connection

Checklist

• My pull request represents one logical piece of work
• My commits are related to the pull request and look clean
• I tested my changes locally with pytest -vv
• I formatted my code with black .

[lpillmann]

It looks very good to me!

As we discussed, this is an important step that sets the foundation for integration tests. With these changes we can easily add new test scenarios and expand the coverage as needed 🎉

I noticed the automated tests failed and looks like the credentials are missing somehow. Good to merge after it is solved imo :)