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/pyroute2/default.nix

@@ -1,12 +1,11 @@
-{stdenv, buildPythonPackage, fetchurl}:
+{stdenv, buildPythonPackage, fetchPypi}:
 
 buildPythonPackage rec {
   pname = "pyroute2";
   version = "0.5.2";
-  name = "${pname}-${version}";
 
-  src = fetchurl {
-    url = "mirror://pypi/p/pyroute2/${name}.tar.gz";
+  src = fetchPypi {
+    inherit pname version;
     sha256 = "42bf74495d95a0196a74dd171357f660175aba2bfc23f9b5f63e3830ccbef9ac";
   };