Testing for Validation

[RajNilkar]

Instructions: Create tests for Validation based on Ruleset

The goal is for Redux to check if the user input is correct and to test for validation based on the ruleset written in the internal document of Capstone Redux Project and verify that the checks work on the backend and frontend.

[ScottBBarfuss]

I pushed an update to about finish the validation path for NPC_SHORTESTPATH on the backend. The problem constructor now performs instance validation instead of allowing invalid graphs to fall through. Also, the solved visualization now respects edge direction