pybedtools: Disable tests on python3 due to TypeError issue

Ran small example on website to verify package isn't totally dead.

pkgs/pybedtools.nix

@@ -1,4 +1,4 @@
-{ lib, fetchFromGitHub, buildPythonPackage
+{ lib, fetchFromGitHub, buildPythonPackage, isPy3k
 , cython, bedtools
 , zlib, six, pysam, pytest, psutil, pyaml }:
 
@@ -24,9 +24,12 @@ buildPythonPackage rec {
     python setup.py cythonize
   '';
 
+  # TypeError: don't know how to make test from: <Logger pybedtools.logger (INFO)>
+  doCheck = !isPy3k;
+
   meta = with lib; {
     homepage = "http://daler.github.io/pybedtools";
     description = "pybedtools wraps and extends BEDTools and offers feature-level manipulations from within Python.";
     license = licenses.lgpl2Plus;
   };
-}
+}