Kuba Szostak in your example if you switch to require instead of define it works. Define is for defining a new module. In the example you provided require, which loads existing modules, will work.
If you want to define a new module take a look at the  Write a class help topic which shows how to create the module and load it into your app.
Revised version of your code:
<!DOCTYPE html>
<html>
<head>
  <title>Create a Map</title>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
  <link rel="stylesheet" href="http://js.arcgis.com/3.13/dijit/themes/claro/claro.css">
  <link rel="stylesheet" href="http://js.arcgis.com/3.13/esri/css/esri.css">
  <style>
    html, body, #mapDiv {   padding: 0;   margin: 0;   height: 100%;   }
  </style>
  <script src="http://js.arcgis.com/3.13/"></script>
  <script>
    var map;
    //require(["esri/map", "dojo/domReady!"], function(Map) {
    //  map = new Map("mapDiv", {
    //    center: [-56.049, 38.485],
    //    zoom: 3,
    //    basemap: "streets"
    //  });
    //});
  </script>
  <script>
  require([
  "dojo/ready",   "dojo/on",  "dojo/dom-construct",
  "esri/config",  "esri/map",  "esri/graphic",   "esri/symbols/PictureMarkerSymbol",
  "esri/layers/WMSLayer",   "esri/geometry/Extent",   "esri/geometry/Point",
  "esri/geometry/webMercatorUtils",   "esri/InfoTemplate",   "esri/dijit/InfoWindowLite"],
    function () {
      console.log("dojo initialized.");
    });
  </script>
</head>
<body class="claro">
  <div id="mapDiv"></div>
</body>
</html>