title: AWS CloudFormation keys not accepting special characters
body: <p>I have noticed that AWS CloudFormation does not like special characters. </p>
  
  <p>When I update a <code>key:value</code> pair in our <code>pipeline.yml</code> file with special char 
  e.g. <code>PAR_FTP_PASS: ^XoN*H89Ie!rhpl!wan=Jcyo6mo</code>, I see the following error:</p>
  
  <pre><code>parameters[5] ParameterKey, ParameterValue or UsePreviousValue expected
  </code></pre>
  
  <p>I am able to update the value through the AWS CloudFormation UI. </p>
  
  <p>It seems like the issue is to do with AWS CloudFOrmation parsing the yml file.</p>
  
  <p>Is there a workaround with this issue?</p>