Add Dockerfile and update gitignore

.gitignore

@@ -56,4 +56,5 @@ pyvenv.cfg
 major-domo-service-creds.json
 get-monthly.py
 team-rocket*
-card-creation/
+card-creation/
+.dockerignore

Dockerfile

@@ -0,0 +1,11 @@
+FROM python:3.8-slim
+
+WORKDIR /usr/src/app
+
+RUN apt-get update && apt-get install -y git
+COPY requirements.txt ./
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY . .
+
+CMD [ "python", "./majordomo.py" ]