WIP adding *untested* implementation of the weights

[osofr]

Per @nhejazi and #12

• This implements the weights option throughout the package for the two available bin_estimators speedglm and glm.

• The implementation is untested and has not been debugged. No test cases have been written yet.

• The most difficult and potentially error prone use case is when pooling bin hazards into a single regression (`pool=TRUE'). While the weights option should still work in that case, it is a more difficult implementation, and hence, more susceptible to errors:

https://github.com/osofr/condensier/blob/weights/R/BinOutModelClass.R#L24-L43

[osofr]

Closing because #12