Update readmes.

README.md

@@ -7,7 +7,7 @@ This repo contains the components of Water Data For The Nation:
 - [`wdfn-server`](wdfn-server): A Flask web application that is used to create server-rendered pages for USGS water data
 - [`assets`](assets): Client-side Javascript, CSS, images, etc.
 
-The application has been developed using Python 3.6 and Node.js 14.x. This is a work in progress.
+The application has been developed using Python 3.8.x and Node.js 14.x. This is a work in progress.
 
 ## Install dependencies
 

wdfn-server/README.md

@@ -7,7 +7,7 @@ This project produces server-rendered HTML pages for Water Data For The Nation.
 1. Create a virtualenv and install the project's Python requirements.
 
 ```bash
-virtualenv --python=python3.6 env
+virtualenv --python=python3.8 env
 env/bin/pip install -r requirements.txt
 ```