[PYLINT-FLAKE8][account_voucher_tax, hr_expense_replenishment, hr_expense_replenishment_tax,invoice_datetime] Pylint and Flake8 were applied to this modules
[FLAKE8][invoice_datetime] the invoice.py file has the compute function with many returns that are not supported by pylint/flake8 so was mutted
[PYLINT][invoice_datetime] An error renaming a variable was resolved related to w0622 pylint error
[WARNING][account_refund_early_payment] A warning was fixed due to a variable named equal like a model field in account_invoice_refund
Merge pull request #60 from vauxoo-dev/8.0-pylint-flake8-dev-sergio

[PYLINT-FLAKE8][addons-vauxoo] Pylint and Flake8 actions over some modules done for version 8