title: Elastica or ElasticSearch remove field from all documents
body: <p>I am wondering whether Elastica or ElasticSearch provides the ability to remove a single  field from all documents in a given index. I have found the correct way to do this in the REST API, but when trying to use it, it gives a syntax error.</p>
  
  <p>I wrote </p>
  
  <pre><code>curl -XPOST localhost:9200/products/product/O2bMZYRek5/_update -d '{
  "script": "ctx._source.remove("Color")"
  }'
  </code></pre>
  
  <p>which returned </p>
  
  <pre><code>{"error":"JsonParseException[Unexpected character ('C' (code 67)): was expecting comma to separate OBJECT entries\n at [Source: [B@fddc294; line: 2, column: 32]]","status":500}
  </code></pre>