Eliminate implementation-specific tests

[canweriotnow]

Inspired by a review of #149 (fix for #148) - a new test was failing based on a (IMHO) poorly constructed state atom in the robot-names exercise example; one of the beauties of Clojure, and, a fortiori, testing in Clojure is being able to test pure functions with pure functions, rather than relying on underlying implementation details for mutable state.

This issue calls for a review of all tests in @exercism/clojure and there related examples to ensure that tests only check for functionality without relying on the behavior of particular stateful constructs to pass.

[bobbicodes]

I understand this is from 5 years ago but I think it raises a strong point that likely should still be visited! I imagine that many of the unit tests were ported from other tracks without much regard for how we would actually do it ;)

[rthouvenin]

I was also very surprised to see that the tests expect reset-name to have side-effects rather than return a robot with a different name. This is unlike any clojure code I've seen