pythonPackages.nest-asyncio: build without tests

Tests fail on v1.2.1 & old v1.2.0.
This disables the tests to allow this package to build.
There doesn't seem to be an easy fix to allow running tests, b/c
the GitHub repo doesn't have release tags.

pkgs/development/python-modules/nest-asyncio/default.nix

@@ -14,6 +14,11 @@ buildPythonPackage rec {
     sha256 = "7d4d7c1ca2aad0e5c2706d0222c8ff006805abfd05caa97e6127c8811d0f6adc";
   };
 
+  # tests not packaged with source dist as of 1.2.1/1.2.2, and
+  # can't check tests out of GitHub easily without specific commit IDs (no tagged releases)
+  doCheck = false;
+  pythonImportsCheck = [ "nest_asyncio" ];
+
   meta = with stdenv.lib; {
     homepage = https://github.com/erdewit/nest_asyncio;
     description = "Patch asyncio to allow nested event loops";