v0.1.0

Main changes:

• new available criterion: Ordinary Least Square
• new arguments transform_obs and transform_sim in estim_param function for dynamic transformation of observations and/or simulations
• new argument satisfy_par_const in estim_param function for defining contraints on the parameters to estimate (e.g. inequality constraints between parameters)
• estim_param now displays total elapse time
• some bugs fixed
• license changed to CeCILL-C