Easy spacing fixes, trailing stuff

Remove useless trailing \
Remove trailing spaces
Add missing empty lines

autopep8 -ir -j2 --select=E301,E302,E502,W291,W293,W391 .

Diff quickly checked.

weboob/capabilities/library.py

@@ -34,12 +34,14 @@ class Book(CapBaseObject):
     date =      DateField('The due date')
     late =      Field('Are you late?', bool)
 
+
 class Renew(CapBaseObject):
     """
     A renew message.
     """
     message = StringField('Message')
 
+
 class ICapBook(ICapCollection):
     """
     Library websites.