fix: switch http2 to https due to spdy issues and http2 incompatibility with superagent out of box

Author: niftylettuce

index.js

@@ -1,5 +1,5 @@
 const http = require('http');
-const http2 = require('http2');
+const https = require('https');
 const util = require('util');
 
 const Cabin = require('cabin');
@@ -175,10 +175,10 @@ class API {
       else app.use(this.config.routes);
     }
 
-    // start server on either http or http2
+    // start server on either http or https
     const server =
       this.config.protocol === 'https'
-        ? http2.createSecureServer(this.config.ssl, app.callback())
+        ? https.createServer(this.config.ssl, app.callback())
         : http.createServer(app.callback());
 
     // expose app, server, client