moving to node-fetch coz axios is causing issues with scrapingAnt

lib/notification/adapter/mattermost.js

@@ -1,6 +1,6 @@
 const { markdown2Html } = require('../../services/markdown');
 const { getJob } = require('../../services/storage/jobStorage');
-const axios = require('axios');
+const fetch = require('node-fetch');
 
 /**
  * sends new listings to mattermost
@@ -21,9 +21,13 @@ exports.send = ({ serviceName, newListings, notificationConfig, jobKey }) => {
     (o) => `| [${o.title}](${o.link}) | ` + [o.address, o.size.replace(/2m/g, '$m^2$'), o.price].join(' | ') + ' |\n'
   );
 
-  return axios.post(`${webhook}`, {
-    channel: channel,
-    text: message,
+  return fetch(webhook, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: {
+      channel: channel,
+      text: message,
+    },
   });
 };