fix(EditableCell): fix linting errors

lib/editor/components/timetable/EditableCell.js

@@ -1,6 +1,6 @@
 // @flow
 
-// $FlowIgnore - TODO: need to update Flow to like the useEffect or useState hooks
+// $FlowFixMe
 import React, {useEffect, useState} from 'react'
 import moment from 'moment'
 
@@ -231,7 +231,7 @@ function EditableCell (props: Props) {
         cancel()
       } else {
         const duration = moment.duration(data)
-        // $FlowExpectedError - Flow throws "mixed" type linting error, but this should be okay
+        // $FlowFixMe - Flow type error
         const value = duration.isValid() ? duration.valueOf() / 1000 : false
 
         if (value !== false) {