Added support for redd.it PNG.

src/methods/redditImage.js

@@ -2,8 +2,15 @@
 
 const util = require('util');
 const config = require('config');
+const path = require('path');
 const fetch = require('node-fetch');
 
+const extensions = require('../extensions.json');
+
+function reverseLookup(extension) {
+    return Object.keys(extensions).find(mime => extensions[mime] === extension);
+};
+
 function redditImage(post) {
     return Promise.resolve({
         album: null,
@@ -12,7 +19,7 @@ function redditImage(post) {
             url: post.url,
             title: post.title,
             datetime: post.datetime,
-            type: 'image/jpeg',
+            type: reverseLookup(path.extname(post.url)),
             original: post
         }]
     });