Wrote a function to get a spots offsets to reach valid adjacent spots. Changed the dropPieceInColumn function to also return the spot index that the piece settled in in addition to the resulting gameboard.
Renamed the function created in my last commit as it was only return offsets, not indices. Wrote another function with the old name which takes those offsets and returns you a vector of the valid adjacent spot indices.
Changed getSpotsAdjacentIndices to return a map containing valid adjacent indices to the offset used to get there. This is necessary for later functions when trying to determine if the game is over so we can continue looking in a direction for 4 in a row.