Add even more dev outputs

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

@@ -10,6 +10,8 @@ if isPyPy then null else buildPythonPackage rec {
     sha256 = "1mffyilq4qycm8gs4wkgb18rnqil8a9blqq77chdlshzxc8jkc5k";
   };
 
+  outputs = [ "out" "dev" ];
+
   propagatedBuildInputs = [ libffi pycparser ];
   buildInputs = [ pytest ];
 

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

@@ -12,6 +12,8 @@ buildPythonPackage rec {
     sha256 = "0zi3v9nsmv9j27d0c0m1dvqyvaxz53g8m0aa1h3qanxs4irkwi4w";
   };
 
+  outputs = [ "out" "dev" ];
+
   nativeBuildInputs = [ pytest ];
   propagatedBuildInputs = [ urllib3 idna chardet certifi ];
   # sadly, tests require networking

pkgs/development/python-modules/urllib3/default.nix

@@ -12,6 +12,8 @@ buildPythonPackage rec {
     sha256 = "0kyvc9zdlxr5r96bng5rhm9a6sfqidrbvvkz64s76qs5267dli6c";
   };
 
+  outputs = [ "out" "dev" ];
+
   NOSE_EXCLUDE = stdenv.lib.concatStringsSep "," [
     "test_headers" "test_headerdict" "test_can_validate_ip_san" "test_delayed_body_read_timeout"
     "test_timeout_errors_cause_retries" "test_select_multiple_interrupts_with_event"