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`.
Regression introduced by 76beb08313.
With version 0.7.15 a few additional dependencies are needed by trezor,
mainly a newer version of protobuf bindings and requests.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Cc: @np
