Adds tests for delete command

[geofflamrock]

This PR is part of a series that adds tests:

• Adds tests for list command #30
• Adds tests for new command #31
• Adds tests for delete command #32
• Adds tests for switch command #33
• Adds tests for status command #34
• Adds tests for update command #45

This PR adds tests for the delete command as well as a --force option to not confirm the delete.