Fix route to avoid remove trailing slash in collection endpoints.

accountant/views/accounts.py

@@ -122,7 +122,7 @@ range_parser.add_argument(
 
 
 # pylint: disable=no-self-use
-@ns.route('/')
+@ns.route('')
 @ns.doc(
     security='apikey',
     responses={

accountant/views/operations.py

@@ -90,7 +90,7 @@ account_range_parser.add_argument(
 
 
 # pylint: disable=no-self-use
-@ns.route('/')
+@ns.route('')
 @ns.doc(
     security='apikey',
     responses={

accountant/views/scheduled_operations.py

@@ -68,7 +68,7 @@ account_id_parser.add_argument(
 
 
 # pylint: disable=no-self-use
-@ns.route('/')
+@ns.route('')
 @ns.doc(
     security='apikey',
     responses={