Add Brotli compression as the default compresion

lib/metadata/policies.js

@@ -786,13 +786,13 @@ var policies = {
         "isAbnormalThreshold": 10,
         "hasOffenders": true
     },
-    "gzipCompression": {
+    "compression": {
         "tool": "redownload",
-        "label": "Gzip compression",
-        "message": "<p>Measures the number of bytes that could be saved by compressing file transfers.</p><p>Gzip is a powerfull weight reducer and should be enabled on text-based assets in your server's configuration. Note that gzipping small files (< 1 KB) is arguable, and that some assets such as images should not be gzipped as they are already compressed. <a href=\"https://gist.github.com/gmetais/971ce13a1fbeebd88445\" target=\"_blank\">Here</a> is a list of Content-Types that should be gzipped.</p>",
-        "isOkThreshold": 5125,
-        "isBadThreshold": 81920,
-        "isAbnormalThreshold": 153600,
+        "label": "Gzip/Brotli compression",
+        "message": "<p>Measures the number of bytes that could be saved by compressing textual files.</p><p>Gzip is a good old weight reducer. But Brotli is a new-generation compression tool and it gives better results. All major server systems are now compatible with Brotli.</p><p>Note that compressing small files (< 1 KB) is arguable, and that some assets such as images should not be gzipped as they are already compressed. <a href=\"https://gist.github.com/gmetais/971ce13a1fbeebd88445\" target=\"_blank\">Here</a> is a list of Content-Types that should be compressed.</p>",
+        "isOkThreshold": 20480,
+        "isBadThreshold": 204800,
+        "isAbnormalThreshold": 409600,
         "hasOffenders": true,
         "unit": 'bytes'
     },
@@ -932,7 +932,7 @@ var policies = {
         "label": "Woff 2",
         "message": "<p>The fonts listed here could be lighter if they were served with the latest woff 2 font file format. Some online tools can help you easily convert older formats to woff 2.</p>",
         "isOkThreshold": 0,
-        "isBadThreshold": 61440,
+        "isBadThreshold": 51200,
         "isAbnormalThreshold": 122880,
         "hasOffenders": true,
         "unit": 'bytes'

lib/metadata/scoreProfileGeneric.json

@@ -5,8 +5,8 @@
             "policies": {
                 "totalWeight": 5,
                 "imageOptimization": 2,
-                "imagesTooLarge": 2,
-                "gzipCompression": 2,
+                "imagesTooLarge": 1,
+                "compression": 2,
                 "fileMinification": 1
             }
         },