Add the Intl API to the modermizr checks

Also change to to not minify, because it will be minified by webpack
anyway so we may as wel have a halfway sensible diff next time.

.modernizr.json

@@ -1,5 +1,5 @@
 {
-    "minify": true,
+    "minify": false,
     "enableClasses": false,
     "feature-detects": [
         "test/css/animations",
@@ -29,6 +29,7 @@
         "test/crypto",
         "test/iframe/sandbox",
         "test/json",
+        "test/intl",
         "test/network/fetch",
         "test/storage/localstorage",
         "test/window/resizeobserver"