title: using graphql github api to filter pr's merged between two dates
body: <p>if you sign into <a href="https://developer.github.com/v4/explorer/" rel="nofollow noreferrer">https://developer.github.com/v4/explorer/</a>
  and run this query </p>
  
  <pre><code>{
    search(query: "org:ruby is:pr merged:&lt;2019-07-11", type: ISSUE, last: 5) {
      edges {
        node {
          ... on PullRequest {
            url 
            mergedAt
            commits(first: 12) {
              totalCount 
            }
          }
        }
      }
    }
  }
  
  </code></pre>
  
  <p>I can get all the pr that were merged before 2019-07-11
  I would like to get the pr's merged before 2019-07-11 AND after  2019-07-04</p>
  
  <p>using <code>query: "org:ruby is:pr merged:&lt;2019-07-11 and is:pr merged:&gt;2019-07-04 "</code> does not filter. Is there an elegant way to do this?</p>