Update dependency semantic-ui to v2.5.0

Author: renovate[bot]

playground/index.html

@@ -5,7 +5,7 @@
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <title>react-jsonschema-form-semanticui playground</title>
-  <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.2.12/semantic.min.css" />
+  <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.5.0/semantic.min.css" />
   <script src="//cdn.polyfill.io/v2/polyfill.min.js"></script>
 
 </head>

playground/index.prod.html

@@ -5,7 +5,7 @@
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <title>react-jsonschema-form-semanticui playground</title>
-  <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.2.12/semantic.min.css" />
+  <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.5.0/semantic.min.css" />
   <link rel="stylesheet" href="./styles.css">
   <script src="//cdn.polyfill.io/v2/polyfill.min.js"></script>
 </head>