Add update-dat tox target for convenient data file updating

tox.ini

@@ -39,3 +39,21 @@ commands = sphinx-build -N -b html docs {envtmpdir}/sphinx -W
 skip_install = true
 deps =
 commands = python scripts/check_headers.py
+
+[testenv:update-dat]
+use_develop = true
+deps = -r update/requirements.txt
+allowlist_externals = bash
+commands =
+  -bash -c 'update/at_postleitzahl.py > stdnum/at/postleitzahl.dat'
+  -bash -c 'update/be_banks.py > stdnum/be/banks.dat'
+  -bash -c 'update/cfi.py > stdnum/cfi.dat'
+  -bash -c 'update/cn_loc.py > stdnum/cn/loc.dat'
+  -bash -c 'update/gs1_ai.py > stdnum/gs1_ai.dat'
+  -bash -c 'update/iban.py > stdnum/iban.dat'
+  -bash -c 'update/imsi.py > stdnum/imsi.dat'
+  -bash -c 'update/isbn.py > stdnum/isbn.dat'
+  -bash -c 'update/isil.py > stdnum/isil.dat'
+  -bash -c 'update/my_bp.py > stdnum/my/bp.dat'
+  -bash -c 'update/nz_banks.py > stdnum/nz/banks.dat'
+  -bash -c 'update/oui.py > stdnum/oui.dat'