reflected is now passed as an argument in p
an other argument "dt_saving" is introduced in p for Gillepsie, which allows one to save results every dt_saving step instead of fixed number. if not specified, only last time step is saved.

Agent file: work in progress, we should remove competition kernel and carrying capacity
Gillepsie: modified updates to use kernel that we now pass as arguments through the parameter dictionary p
runworld: for now we only modified std update but this should be done for all the project

We have modified Agent file with carrying capacity and competition kernel using pdf funtion from Distributions.jl
However this will soon change.