poretools: version number to commit date

pkgs/applications/science/biology/poretools/default.nix

···
 
 pythonPackages.buildPythonPackage rec {
   pname = "poretools";
-  version = "0.6.0";
+  version = "unstable-2016-07-10";
   name = "${pname}-${version}";
 
   src = fetchFromGitHub {