Added force update handling

src/modals/ForceUpdateModal.js

@@ -0,0 +1,23 @@
+import React from "react";
+import { Box, Label, Text } from "theme-ui";
+
+import Modal from "../components/Modal";
+
+function ForceUpdateModal({ isOpen }) {
+  return (
+    <Modal
+      isOpen={isOpen}
+      allowClose={false}
+      style={{ maxWidth: "450px" }}
+    >
+      <Box>
+        <Label py={2}>New Update Available</Label>
+        <Text as="p" mb={2} variant="caption">
+          Please refresh your browser to update to the latest version.
+        </Text>
+      </Box>
+    </Modal>
+  );
+}
+
+export default ForceUpdateModal;