Create a script that runs common test cases against a codebase

[AlvinKuruvilla]

It would be nice if there were a script file that ran weggli using various test cases, such as the ones in the README, for quick use. Thus developers could integrate this with their CI/CD pipeline and have a template to build on.

[felixwilhelm]

Hi Alvin,

good suggestion. I'm happy to take a pull request :)