Prepare for Heroku deployment

- Heroku will bind the app to $PORT

- Add parameter to API to be able to customize the background color of the svg

- Add parameter to API to be able to customize the border color of the svg

- Add SetUp.md section on how to customize your card with URL parameters

Update SetUp.md with a section on how to customize the card

requirements.txt

@@ -1,3 +1,16 @@
-flask==1.1.4
-requests==2.24.0
+autopep8==1.6.0
+certifi==2020.6.20
+chardet==3.0.4
+click==7.1.2
+Flask==1.1.4
+gunicorn==20.1.0
+idna==2.10
+itsdangerous==1.1.0
+Jinja2==2.11.3
+MarkupSafe==2.0.1
+pycodestyle==2.8.0
 python-dotenv==0.14.0
+requests==2.24.0
+toml==0.10.2
+urllib3==1.25.11
+Werkzeug==1.0.1