Tests for BayesInf and general cleanup

Some simple fixes for various test, start on testing Discrepancy, MCMC, BayesInf, BMC, output directory as changeable parameter in BayesInf, general cleanup

src/bayesvalidrox/bayes_inference/mcmc.py

@@ -180,7 +180,7 @@ class MCMC:
                 initsamples = np.swapaxes(np.array([initsamples]),0,1) # TODO: test if this still works with multiple input dists
             except:
                 # when aPCE selected - gaussian kernel distribution
-                inputSamples = self.BayesOpts.engine.ExpDesign.raw_data.T
+                inputSamples = BayesObj.engine.ExpDesign.raw_data.T
                 random_indices = np.random.choice(
                     len(inputSamples), size=self.nwalkers, replace=False
                     )
@@ -206,7 +206,7 @@ class MCMC:
                     initsamples[:, idx_dim] = dist.rvs(size=self.nwalkers)
 
                 # Update lower and upper
-                BayesObj.engine.MetaModel.ExpDesign.bound_tuples = bound_tuples
+                BayesObj.engine.ExpDesign.bound_tuples = bound_tuples
 
         # Check if sigma^2 needs to be inferred
         if Discrepancy.opt_sigma != 'B': # TODO: why !='B'?