use ESM, add server setup, cleanup

Change-Id: Iafac35c2082523ae98c31017d9bad5c4d6e18ef3
diff --git a/client/src/components/Header.js b/client/src/components/Header.js
index d245976..c0408a1 100644
--- a/client/src/components/Header.js
+++ b/client/src/components/Header.js
@@ -32,7 +32,7 @@
             <Menu
                 id="simple-menu"
                 anchorEl={anchorEl}
-                keepMounted
+
                 open={Boolean(anchorEl)}
                 onClose={handleClose}
             >