Fix new pylint issues

The new pylint release removed a few rule sets and added a check for generators. This patch updates Octavia for those changes.

Change-Id: I2261342377e7acb1d2bc4fc742a351dfc66e4305

.pylintrc

@@ -20,11 +20,9 @@ disable=
  anomalous-backslash-in-string,
  arguments-differ,
  attribute-defined-outside-init,
- bad-builtin,
  broad-except,
  fixme,
  global-statement,
- no-init,
  pointless-string-statement,
  protected-access,
  redefined-builtin,
@@ -35,15 +33,12 @@ disable=
  unused-variable,
  useless-super-delegation,
 # "C" Coding convention violations
- bad-continuation,
  invalid-name,
  line-too-long,
  missing-docstring,
  consider-using-f-string,
 # "R" Refactor recommendations
  duplicate-code,
- interface-not-implemented,
- no-self-use,
  too-few-public-methods,
  too-many-ancestors,
  too-many-arguments,

octavia/amphorae/backends/agent/api_server/amphora_info.py

@@ -149,7 +149,7 @@ class AmphoraInfo(object):
                 'iowait': vals[6],
                 'irq': vals[7],
                 'softirq': vals[8],
-                'total': sum([int(i) for i in vals[2:]])
+                'total': sum(int(i) for i in vals[2:])
             }
 
     def _load(self):