Add localization of datetime in public page (#3296)

package.json

@@ -42,7 +42,6 @@
     "coffee-script": "^1.12.5",
     "compression-webpack-plugin": "^0.4.0",
     "css-loader": "^0.28.0",
-    "date-fns": "^1.28.4",
     "dotenv": "^4.0.0",
     "emojione": "^2.2.7",
     "emojione-picker": "^2.2.1",
@@ -57,6 +56,7 @@
     "immutable": "^3.8.1",
     "intersection-observer": "^0.2.1",
     "intl": "^1.2.5",
+    "intl-relativeformat": "^1.3.0",
     "is-nan": "^1.2.1",
     "js-yaml": "^3.8.3",
     "lodash": "^4.17.4",