adapt to 4.0

__init__.py

@@ -1,15 +1,15 @@
 # The COPYRIGHT file at the top level of this repository contains the full
 # copyright notices and license terms.
 from trytond.pool import Pool
-from .production import *
+from . import production
 
 
 def register():
     Pool.register(
-        BOMTree,
-        OpenBOMTreeStart,
-        OpenBOMTreeTree,
+        production.BOMTree,
+        production.OpenBOMTreeStart,
+        production.OpenBOMTreeTree,
         module='production_bom_stock_form', type_='model')
     Pool.register(
-        OpenBOMTree,
+        production.OpenBOMTree,
         module='production_bom_stock_form', type_='wizard')

tryton.cfg

@@ -1,5 +1,5 @@
 [tryton]
-version=3.4.0
+version=4.0
 depends:
     production
     stock_calculation