title: Error: Password contains an illegal unescaped character
body: <p>I'm trying to deploy a Facebook chatbot on Heroku but I'm getting this error:</p>
  
  <pre class="lang-none prettyprint-override"><code>2019-03-26T01:34:39.286607+00:00 app[web.1]: Error: Password contains an illegal unescaped character
  2019-03-26T01:34:39.286618+00:00 app[web.1]: at parseConnectionString (/app/node_modules/mongodb/lib/url_parser.js:298:13)
  2019-03-26T01:34:39.286620+00:00 app[web.1]: at parseHandler (/app/node_modules/mongodb/lib/url_parser.js:129:14)
  2019-03-26T01:34:39.286622+00:00 app[web.1]: at module.exports (/app/node_modules/mongodb/lib/url_parser.js:25:12)
  2019-03-26T01:34:39.286623+00:00 app[web.1]: at deprecated (internal/util.js:67:15)
  2019-03-26T01:34:39.286625+00:00 app[web.1]: at connect (/app/node_modules/mongodb/lib/operations/mongo_client_ops.js:195:3)
  2019-03-26T01:34:39.286626+00:00 app[web.1]: at connectOp (/app/node_modules/mongodb/lib/operations/mongo_client_ops.js:284:3)
  2019-03-26T01:34:39.286628+00:00 app[web.1]: at executeOperation (/app/node_modules/mongodb/lib/utils.js:416:24)
  2019-03-26T01:34:39.286630+00:00 app[web.1]: at MongoClient.connect (/app/node_modules/mongodb/lib/mongo_client.js:169:10)
  2019-03-26T01:34:39.286631+00:00 app[web.1]: at Function.MongoClient.connect (/app/node_modules/mongodb/lib/mongo_client.js:335:22)
  2019-03-26T01:34:39.286633+00:00 app[web.1]: at Timeout.connectToMongo [as _onTimeout] (/app/index.js:37:14)
  </code></pre>
  
  <p>I have used very simple password, but it still shows same error. How can I fix it?</p>
  
  <p>I'm temporarily using <code>01234567890</code> as my password. When I put it into my connection string I get something like</p>
  
  <pre class="lang-none prettyprint-override"><code>mongodb+srv://myuser:&lt;01234567890&gt;@host.gcp.mongodb.net/test?retryWrites=true
  </code></pre>