Cache the last 1000 most recently used API requests in memory

lib/tor.js

@@ -1,6 +1,8 @@
 const Onionoo = require('onionoo');
+const QuickLRU = require('quick-lru');
 
-const onionoo = new Onionoo();
+const lru = new QuickLRU({ maxSize: 1000 });
+const onionoo = new Onionoo({ cache: lru });
 
 const setNodeType = type => node => {
 	node.type = type;

package.json

@@ -17,7 +17,8 @@
     "moment": "2.19.3",
     "nunjucks": "3.0.1",
     "onionoo": "2.0.1",
-    "pretty-bytes": "4.0.2"
+    "pretty-bytes": "4.0.2",
+    "quick-lru": "^1.1.0"
   },
   "devDependencies": {
     "nodemon": "^1.10.2",