ATO-459: cache nunjucks templates

This should reduce disk iops and improve overall performance when rendering templates.

src/config/nunchucks.ts

@@ -3,6 +3,8 @@ import * as nunjucks from "nunjucks";
 import { Environment } from "nunjucks";
 import i18next from "i18next";
 import { returnLastCharactersOnly } from "../utils/phone-number";
+import { getNodeEnv } from "../config";
+import { ENVIRONMENT_NAME } from "../app.constants";
 
 export function configureNunjucks(
   app: express.Application,
@@ -11,7 +13,7 @@ export function configureNunjucks(
   const nunjucksEnv: nunjucks.Environment = nunjucks.configure(viewsPath, {
     autoescape: true,
     express: app,
-    noCache: true,
+    noCache: getNodeEnv() !== ENVIRONMENT_NAME.PROD,
   });
 
   nunjucksEnv.addFilter("translate", function (key: string, options?: any) {