we changed the way we store agents in Simulation. Now it is a vector of vector of agents, and it seems to perform much better. Thus we are merging all this in v1.0

now we need to unit test gillepsiee.jl, and especially the update rates
almost there!

Many changes, we are almost send a full run. We need now to modify constructor of agent, to distinguish between AgentA and AgentNA.
Then we need to continue unit testing with simulation, maybe adding a callback function.
After that, we are good to go.

Changes on type Agent, that is now Agent{T,U}. Added a function increment! for type Agent{MixedAgent,U}.

Test have also been modified, because it seems that this change also changes the random seed.

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