Create tests

We need to create basic tests for the bot.

The first tests should be simple and we should also create a template test for newbies to get acquainted with testing with.

1. Write tests for the following functions: `ping`, `quote`
2. Write a template test function for others to base their tests off of.

Locate the Rust implementations of `ping` and `quote`, then inspect the project's existing test setup. Add basic tests for both functions and a reusable template test for newcomers; done means all three requested test pieces are present and the test suite passes.

Written by the indexing model from the issue text.