Add CacheableDnsHttpAgent.install()

package.json

@@ -68,7 +68,7 @@
         "badge-maker": "^3.3.1",
         "bcryptjs": "~2.4.3",
         "bree": "~7.1.5",
-        "cacheable-lookup": "^6.0.4",
+        "cacheable-lookup": "~6.0.4",
         "chardet": "^1.3.0",
         "check-password-strength": "^2.0.5",
         "cheerio": "^1.0.0-rc.10",

server/cacheable-dns-http-agent.js

@@ -17,6 +17,10 @@ class CacheableDnsHttpAgent {
         this.cacheable.install(https.globalAgent);
     }
 
+    static install(agent) {
+        this.cacheable.install(agent);
+    }
+
     /**
      * @var {https.AgentOptions} agentOptions
      * @return {https.Agent}