fixed filename of prob02_least_obscure_path.py -> prob03_least_obscure_path.py
cs215/unit05/prob03_least_obscure_path_my.py: rewrite dijkstra again
cs215/unit05/prob03_least_obscure_path_my.py: fix obscurity score; it was already a multiplicitive inverse; no need to make it one; this makes it pass!
cs215/unit05/prob03_least_obscure_path_my.py: unicode decode fix
cs215/unit05/prob03_least_obscure_path_my.py: print the final answer!