Bump purgecss to 2.0.6

Author: forsartis

package.json

@@ -18,7 +18,7 @@
     "purgecss"
   ],
   "dependencies": {
-    "@fullhuman/postcss-purgecss": "^1.2.0",
+    "@fullhuman/postcss-purgecss": "^2.0.6",
     "tailwindcss": "^1.2.0"
   }
 }