minor config changes for let's encrypt certbot, stub index.html

.gitignore

@@ -1,4 +1,5 @@
 .coverage
+/.well-known/acme-challenge/
 datastore.dat*
 /docs/_build/
 /l

app.yaml

@@ -30,6 +30,9 @@ handlers:
 - url: /oauth_dropins/static
   static_dir: local/lib/python2.7/site-packages/oauth_dropins/static
 
+- url: /.well-known
+  static_dir: .well-known
+
 - url: /
   static_files: static/index.html
   upload: static/index.html

static/index.html

@@ -0,0 +1 @@
+TODO