title: Elastalert whitelist/blacklist not working
body: <p>So I have a certain query running in (Yelp's) Elastalert and I am trying to filter out logs containing one of several keywords. If I use the <code>any</code> rule type, I get a set of 30 matches to the certain query I have. When I change the ruletype to whitelist:</p>
  
  <pre><code>type: whitelist
  compare_key: message
  ignore_null: true
  whitelist: ["exclude_strings"...]
  </code></pre>
  
  <p>I still get the same 30 matches, even when I know the message field contains the listed strings. I've also tried changing the compare key or the strings, using strings that exactly match the entire field, I've changed the formatting to</p>
  
  <pre><code>whitelist:
  - "string"
  ...
  </code></pre>
  
  <p>and nothing has made a difference. The same thing happens also with the blacklist type. </p>
  
  <p>What am I missing?</p>