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/simpleeval/default.nix

@@ -1,11 +1,10 @@
-{ lib, fetchurl, buildPythonPackage }:
+{ lib, fetchPypi, buildPythonPackage }:
 
 buildPythonPackage rec {
   pname = "simpleeval";
-  name = "${pname}-${version}";
   version = "0.9.5";
-  src = fetchurl {
-    url = "mirror://pypi/s/simpleeval/${name}.tar.gz";
+  src = fetchPypi {
+    inherit pname version;
     sha256 = "0sda13bqg9l4j17iczmfanxbzsg6fm9aw8i3crzsjfxx51rwj1i3";
   };
   meta = {