pythonPackages: remove name attribute`

The `buildPython*` function computes name from `pname` and `version`.
This change removes `name` attribute from all expressions in
`pkgs/development/python-modules`.

While at it, some other minor changes were made as well, such as
replacing `fetchurl` calls with `fetchPypi`.

pkgs/development/python-modules/pyudev/default.nix

@@ -1,14 +1,13 @@
-{ lib, fetchurl, buildPythonPackage
+{ lib, fetchPypi, buildPythonPackage
 , six, systemd, pytest, mock, hypothesis, docutils
 }:
 
 buildPythonPackage rec {
   pname = "pyudev";
-  name = "${pname}-${version}";
   version = "0.21.0";
 
-  src = fetchurl {
-    url = "mirror://pypi/p/pyudev/${name}.tar.gz";
+  src = fetchPypi {
+    inherit pname version;
     sha256 = "0arz0dqp75sszsmgm6vhg92n1lsx91ihddx3m944f4ah0487ljq9";
   };