Bump the version number to 6.1.0

Summary:
- Enable ANP to cope with constant functions
- Make plot's appearance more deterministic
- Replace 'roots' in 'polyratio.m' with 'uvFactor' from toolbox 'NAClab'

This version should be able to handle MIMO systems much better because
of the better root finding algorithm 'uvFactor'.

anp_main.m

@@ -6,7 +6,7 @@
 %           https://blogs.ethz.ch/ricklis
 %           https://github.com/StefanRickli/anp
 %
-%   Version 6.0.1
+%   Version 6.1.0
 %   
 %   
 %   What does it do?: