fix_integers(jump_model::Model)

inputs: jump_model - a model object containing that has been previously solved.

description: fixes the iteger variables ones the model has been solved in order to calculate approximations of dual variables

returns: none (modifies an existing-solved model in the memory). solve() must be run again to solve and getdual veriables

function solve_model()

inputs: EP - a JuMP model representing the energy optimization problem setup - a Dict containing GenX setup flags

description: Solves and extracts solution variables for later processing

returns: results EP model object with a set of DataFrames containing key results