Update README to use Python 3.7+ instead

README.md

@@ -329,7 +329,7 @@ All work on SimpleLogin happens directly on GitHub.
 
 ### Run code locally
 
-The project uses Python 3.6+. First, install all dependencies by running the following command. Feel free to use `virtualenv` or similar tools to isolate development environment.
+The project uses Python 3.7+. First, install all dependencies by running the following command. Feel free to use `virtualenv` or similar tools to isolate development environment.
 
 ```bash
 pip3 install -r requirements.txt