Previously was included but not enabled. The errors fixed are:
app/routes.js:9:16
✖ 9:16 Component definition is missing display name react/display-name
app/routes/contacts/components/Contacts.js:151:49
✖ 151:49 Missing "key" prop for element in iterator react/jsx-key
✖ 167:22 Missing "key" prop for element in iterator react/jsx-key