title: ElasticSearch Search query is not case sensitive
body: <p>I am trying to search query and it working fine for exact search but if user enter lowercase or uppercase it does not work as ElasticSearch is case insensitive.</p>
  
  <p>example</p>
  
  <pre><code>{
      "query" : {
          "bool" : { 
              "should" : {
                  "match_all" : {} 
              },
              "filter" : {
                  "term" : { 
                      "city" : "pune"
                  }
              }
          }
      }
  }
  </code></pre>
  
  <p>it works fine when city is exactly "pune", if we change text to "PUNE" it does not work.</p>