Merge pull request #139 from OpenSourceEcon/dependabot/pip/jinja2-3.1.4

Merging

Author: rickecon

requirements.txt

@@ -5,7 +5,7 @@ Flask-Assets==2.0
 Flask-Markdown==0.3
 gunicorn==22.0.0
 itsdangerous==1.1.0
-Jinja2==2.11.3
+Jinja2==3.1.4
 Markdown==3.2.2
 MarkupSafe==1.1.1
 Pygments==2.15.0