encoding/openapi: add paths:{}

Openapi specs are missing the paths attributes, which is a required attribute. This adds an empty paths attribute to the generated openapi spec.

Change-Id: I18d98da0da0a042acb3f382ad38901f71b6f05d8

Fixes #134

Change-Id: I18d98da0da0a042acb3f382ad38901f71b6f05d8
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/3420
Reviewed-by: Eric Adlam <eadlam@gmail.com>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/encoding/openapi/testdata/oneof-funcs.json b/encoding/openapi/testdata/oneof-funcs.json
index 157b53c..104adcb 100644
--- a/encoding/openapi/testdata/oneof-funcs.json
+++ b/encoding/openapi/testdata/oneof-funcs.json
@@ -4,6 +4,7 @@
       "title": "test",
       "version": "v1"
    },
+   "paths": {},
    "components": {
       "schemas": {
          "MYSTRING": {