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

Introducing new abstract type to distinguish between different types of agents : continuous, discrete or mixed.

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.

* origin/no_C_matrix:
  uploading jld2 wrightfisher unit test
  uploading gillepsie jld2 test
  modifying project.toml and unit test
  Adding many unit test files
  added test files, modifying functioning of update_rates. Looks pretty good right now
  no message
  significantly modifying ABMEv_Gillepse

# Conflicts:
#	src/ABMEv_runworld.jl

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.