Revert "pythonPackages.psutil: 3.4.2 -> 4.3.0"

This reverts commit 86caec1be1.

In this commit tests were re-enabled, but without correctly testing whether it could.
When a package builds it doesn't mean the tests are actually run. This is often seen when it says that 0 tests were run.
Typically this is because the test runner was invoked incorrectly.

By re-enabling the tests, a false impression is generated that the package is tested while in fact it isn't. Furthermore, the Python 3.5
package broke because the tests are invoked incorrectly.

cc @abbradar

pkgs/top-level/python-packages.nix

@@ -17819,13 +17819,17 @@ in modules // {
 
   psutil = buildPythonPackage rec {
     name = "psutil-${version}";
-    version = "4.3.0";
+    version = "3.4.2";
 
     src = pkgs.fetchurl {
       url = "mirror://pypi/p/psutil/${name}.tar.gz";
-      sha256 = "1w4r09fvn6kd80m5mx4ws1wz100brkaq6hzzpwrns8cgjzjpl6c6";
+      sha256 = "b17fa01aa766daa388362d0eda5c215d77e03a8d37676b68971f37bf3913b725";
     };
 
+    # Certain tests fail due to being in a chroot.
+    # See also the older issue: https://code.google.com/p/psutil/issues/detail?id=434
+    doCheck = false;
+
     buildInputs = with self; [ mock ] ++ optionals stdenv.isDarwin [ pkgs.darwin.IOKit ];
 
     meta = {