New login screen (#1331)

* wip

* feat: first draft of auth.config

* chore: auth methodS

* chore: styling

* styling, styling, styling

* feat: Auth notices

* chore: Remove server-rendered pages, move shared/components -> components

* lint

* cleanup

* cleanup

* fix: Remove unused component

* fix: Ensure env variables in prod too

* style tweaks

* fix: Entering SSO email into login form fails
fix: Tweak language around guest signin

app/components/ButtonLarge.js

@@ -0,0 +1,13 @@
+// @flow
+import styled from "styled-components";
+import Button, { Inner } from "./Button";
+
+const ButtonLarge = styled(Button)`
+  height: 40px;
+
+  ${Inner} {
+    padding: 4px 16px;
+  }
+`;
+
+export default ButtonLarge;