Pass github token in headers and not as a query param (#1246)

* Pass github token in headers and not as a query param

* fix lint issue

* Update js/review-app-slack-webhook.js

Co-Authored-By: Christopher DeCairos <christopherd@mozillafoundation.org>

Co-authored-by: Christopher DeCairos <christopherd@mozillafoundation.org>

js/review-app-slack-webhook.js

@@ -17,8 +17,13 @@ const slack_webhook = process.env.SLACK_WEBHOOK;
 // For review app manually created, we have to use the branch name instead.
 if (pr_number) {
   request(
-    `https://api.github.com/repos/${org}/${repo}/pulls/${pr_number}&access_token=${github_token}`,
-    { headers: { "User-Agent": "request" } },
+    `https://api.github.com/repos/${org}/${repo}/pulls/${pr_number}`,
+    {
+      headers: {
+        "User-Agent": "request",
+        Authorization: `token ${github_token}`
+      }
+    },
     function(error, response, body) {
       if (!error && response.statusCode === 200) {
         const pr_title = JSON.parse(body)["title"];