Add API test suite

One of the current major issues with Red October development is the lack of automated API tests. The current set of tests will make sure that there are no functionality regressions inside the functions, but does not test whether or not the APIs that are exposed via serve are consistent.

The basic regression tests for all the endpoints listed in the README.md should be covered. The functionality of the APIs and JSON parsing should be tested, as well as the message routing logic. The inner logic of the packages does not need to be tested here since the packages have their own tests.