Update Dockerfile.test

This is to run the coverage module through docker

backend/tests/Dockerfile.test

@@ -1,16 +1,13 @@
-# We Use an official Python runtime as a parent image
+# dockerfile.test
 FROM python:3.12-slim
 
-# Allows docker to cache installed dependencies between builds
 COPY requirements.txt requirements.txt
 RUN pip install --no-cache-dir -r requirements.txt
 
-# Mounts the application code to the image
+RUN pip install coverage
+
 RUN mkdir /app
 COPY . /app
 WORKDIR /app
 
-EXPOSE 8000
-
-# Runs migrations and starts the server
-CMD ["sh", "-c", "python manage.py migrate && python manage.py runserver 0.0.0.0:8000"]
+CMD ["sh", "-c", "coverage run --source='.' manage.py test && coverage report"]