fix(tests): Adjust tolerance in Ludlow2016 concentration test

Random perturbations added to concentrations result in fluctuations in the measured scatter. This fix adds enough buffer to account for that.

testSuite/test-concentration-Ludlow2016.pl

@@ -34,7 +34,7 @@
 	 mean             => 1.077,
 	 meanTolerance    => 0.040,
 	 scatter          => 0.114,
-	 scatterTolerance => 0.005
+	 scatterTolerance => 0.008
      }
     );