fix iterateObs() not being called with enough parameters.

[potterzot]

Hi Darin - I was super happy to come across your Conley SE implementation, thanks! When I was incorporating it into a package I had to make some changes to get it to run. It seems like maybe the iterateObs() function wasn't being called with the dt, Xvars, balanced_pnl, and verbose parameters from ConleySEs().

The only substantive difference in the PR is the calls to iterateObs() from ConleySEs(). The others are superfluous and probably a result of me just coping the entire function over from my package files.

PS - Your work on conflict and commodity prices is interesting. I was looking at conflict and resource scarcity a la this paper but haven't had a chance to revisit it recently:

Almer, Christian, Jérémy Laurent-Lucchetti, and Manuel Oechslin. 2017. “Water Scarcity and Rioting:
Disaggregated Evidence from Sub-Saharan Africa.” Journal of Environmental Economics and Management 86. Elsevier BV:193–209. https://doi.org/10.1016/j.jeem.2017.06.002.