updated CMC code (#474)

* switched from symbolic arrays to list of symbolic parameters. Needed to be able to set tunable flag for individual parameters of the array. Added untune! utility function to set tunable flag to false on list elements.

* added new approach to set tunable flag for the connection matrix also to the tutorial

* use generate_weight_param also in StimulusBlox and ObserverBlox connectors and set standard connection weight to non-tunable

* fixed and cleaned code

* minor changes

* update MTK compat

* added Project.toml to test

* fixed MTK compat once more

* added more packages to test environment needed in GraphDynamics tests

* remove test deps and unnecessary deps

* add Test to tect project

* remove Test dep from main Project

* add missing test deps

* add Statistics dep

* removed [extras] from Project.toml

* added [extras] again.

---------

Co-authored-by: haris organtzidis <organtzh@gmail.com>

test/datafitting.jl

@@ -187,14 +187,17 @@ end
     indices = Dict(:dspars => collect(1:np))
     # Noise parameter mean
     modelparam[:lnα] = zeros(Float64, 2, nrr);        # intrinsic fluctuations, ln(α) as in equation 2 of Friston et al. 2014 
+    modelparam[:lnα] = zeros(Float64, 2, nrr);        # intrinsic fluctuations, ln(α) as in equation 2 of Friston et al. 2014 
     n = length(modelparam[:lnα]);
     indices[:lnα] = collect(np+1:np+n);
     np += n;
     modelparam[:lnβ] = [-16.0, -16.0];                # global observation noise, ln(β) as above
+    modelparam[:lnβ] = [-16.0, -16.0];                # global observation noise, ln(β) as above
     n = length(modelparam[:lnβ]);
     indices[:lnβ] = collect(np+1:np+n);
     np += n;
     modelparam[:lnγ] = [-16.0, -16.0];                # region specific observation noise
+    modelparam[:lnγ] = [-16.0, -16.0];                # region specific observation noise
     indices[:lnγ] = collect(np+1:np+nrr);
     np += nrr
     indices[:u] = idx_u