[8.0] Port the module 'account_move_template' to the new API

This PR contains the module ***account_move_template*** ported to the new API.
Test and installation seems to me ok.

Let's see what will be the TravisCI response and your reviews :wink: 
Wy not using a multi?
```
@api.multi
def _get_template_line(self, line_number):
```