**Acceptance Criteria:**
[ ] Define route for /revision/{id}
[ ] Define route handler for revision that handles the following:
[ ] Request:
[ ] **Must support** HTTP GET **only**
[ ] Request body **must** be empty
[ ] Request headers:
[ ] **Must support** If-Modified-Since: only if the result set has changed since this date
[ ] **Must support** If-None-Match: only if the result set's etag is different from this
[ ] Response:
[ ] Response **must return** JSON
[ ] Responses JSON must have structure:
```
{
"response": {
"id": "889268680",
"page_id": 83784732,
"title": "Some really great title",
"user": "The Blade of the Northern Lights",
"html": "<div>...A lot of content...</div>"
}
}
```
[ ] html **must contain** the HTML output equivalent to /index.php?title=<title>&action=render
[ ] Response headers **must contain**:
[ ] Last-Modified: last time this result set was modified
[ ] ETag: etag for this result set
[ ] Expires: far future (should be immutable)