add user and contributor logos

README.md

@@ -2,6 +2,19 @@
 
 !["Greenlock Function"](https://git.coolaj86.com/coolaj86/greenlock.js/raw/branch/master/logo/from-not-secure-to-secure-url-bar.png "from url bar showing not secure to url bar showing secure")
 
+<table>
+  <tr>
+    <td><a href="https://medium.com/@bohou/secure-your-nodejs-server-with-letsencrypt-for-free-f8925742faa9"><img src="https://git.coolaj86.com/coolaj86/greenlock.js/raw/branch/master/logo/ibm-301x112.png"></a></td>
+    <td><a href="https://github.com/mozilla-iot/le-store-certbot/issues/4"><img src="https://git.coolaj86.com/coolaj86/greenlock.js/raw/branch/master/logo/mozilla-iot-301x112.png"></a></td>
+    <td><a href="https://github.com/digitalbazaar/bedrock-letsencrypt"><img src="https://git.coolaj86.com/coolaj86/greenlock.js/raw/branch/master/logo/digital-bazaar-301x112.png"></a></td>
+  </tr>
+  <tr>
+    <td><a href="https://github.com/beakerbrowser/homebase"><img src="https://git.coolaj86.com/coolaj86/greenlock.js/raw/branch/master/logo/beaker-browser-301x112.png"></a></td>
+    <td><a href="https://telebit.cloud"><img src="https://git.coolaj86.com/coolaj86/greenlock.js/raw/branch/master/logo/telebit-301x112.png"></a></td>
+    <td><a href="https://ppl.family"><img src="https://git.coolaj86.com/coolaj86/greenlock.js/raw/branch/master/logo/ppl-301x112.png"></a></td>
+  </tr>
+</table>
+
 Greenlock&trade; for Express.js
 =================
 <small>formerly letsencrypt-express</small>