Fix flake8 errors and warnings

We add the flake8 configuration used so we ensure everyone uses the same.
We remove the usage of __all__ for non public API.
When possible, we rationalize the class name according to its __name__ and module.

issue9082
review297061002

.flake8

@@ -0,0 +1,2 @@
+[flake8]
+ignore=E123,E124,E126,E128,W503

product.py

@@ -6,9 +6,6 @@ from trytond.pool import PoolMeta
 from trytond.pyson import Eval
 
 
-__all__ = ['Template', 'Product']
-
-
 class Template(metaclass=PoolMeta):
     __name__ = 'product.template'
 

setup.py

@@ -80,8 +80,8 @@ setup(name=name,
     keywords='tryton stock lot unit serial',
     package_dir={'trytond.modules.stock_lot_unit': '.'},
     packages=(
-        ['trytond.modules.stock_lot_unit'] +
-        ['trytond.modules.stock_lot_unit.%s' % p for p in find_packages()]
+        ['trytond.modules.stock_lot_unit']
+        + ['trytond.modules.stock_lot_unit.%s' % p for p in find_packages()]
         ),
     package_data={
         'trytond.modules.stock_lot_unit': (info.get('xml', [])
@@ -94,7 +94,8 @@ setup(name=name,
         'Framework :: Tryton',
         'Intended Audience :: Developers',
         'Intended Audience :: Manufacturing',
-        'License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)',
+        'License :: OSI Approved :: '
+        'GNU General Public License v3 or later (GPLv3+)',
         'Natural Language :: Bulgarian',
         'Natural Language :: Catalan',
         'Natural Language :: Chinese (Simplified)',

stock.py

@@ -9,13 +9,6 @@ from trytond.pyson import Eval, Bool
 
 from .exceptions import LotUnitQuantityError
 
-__all__ = [
-    'Lot', 'Move', 'Inventory', 'InventoryCount',
-    'ShipmentIn', 'ShipmentInReturn',
-    'ShipmentOut', 'ShipmentOutReturn',
-    'Production',
-    ]
-
 
 class Lot(metaclass=PoolMeta):
     __name__ = 'stock.lot'