Share link expiration update and small fixes

app/corpora/routes.py

@@ -76,6 +76,7 @@ def corpus(corpus_id):
         return redirect(url_for('.corpus', corpus_id=corpus.id))
     now = datetime.utcnow()
     payload = {
+            'exp': now + timedelta(weeks=1),
             'iat': now,
             'iss': current_app.config['SERVER_NAME'],
             'sub': corpus.hashid