code refactoring
- new method best_neuron
- rename best_neurons in evaluate_neurons
- find_best _group can now take only obs in arg
 add col and row attribute to neuron
change sigmoid function
add option to not decrease weight update of neighbor
new method to compute the mean of the best distance
new ruby script to rename SCI in file name to healthy
change for using 1 kohonen network for each brain state
typo
working method using kohonen