Add automated testing

[mikeybinns]

This is a living issue to track adding automated tests to all our packages. Some packages I don't know how they would be tested, some packages I know how to test them, but I haven't had time to add them yet.

• Blocks helpers package
• Browserslist config package
• CLI package
• • SVG command
• • setup command
• • setup database command
• • pull database command
• • pull media command
• Coding standards package
• Compiler package
• Date PHP package
• ESLint config package
• Init testing package
• Test utils package
• WordPress tests helper