gps: +1 failing test: single path
gps: +1 test pass: single path
gps: +1 failing test: single path (1 3)
gps: +1 test pass: single path (1 3)
gps: +1 failing test: should solve two step path (1 2 3)
gps: +1 test pass: should solve two step path (1 2 3)
gps: +1 failing test: should solve single path (reversed vertex list)
maximum refactor
gps: +1 test pass: should solve single path (reverse vertex list)