[x] Remove all non-essential solvers (it's confusing);
[x] Move the re-parametrisation of the Gamma and Beta distributions somewhere else (it's going to be useful when we talk about priors for the parameters -- reparametrising in terms of mean and standard deviation is a great idea -- but not for this step);
[x] Remove noise on parameters beta (transmission rate) and gamma (recovery rate): these should be fixed for a given simulation;
[x] Add (multiplicative) noise to the simulated trajectory. R code with something similar can be found here.
beta(transmission rate) andgamma(recovery rate): these should be fixed for a given simulation;