Create prod Dockerimage from alpine base image

[alexlaw528]

Fixes #177

What changes did you make?

• Added a production Docker image using alpine as base-image.

Why did you make the changes (we will use this info to test)?

• Current Docker image is meant for development. It utilizes a larger base-image and contains dependencies unused in production.
• Reduced image size from 1.26 GB to 392.06 MB

Deploy prod environment locally

• Run following commands from/peopledepot root directory:

• Build production image as "alpine-pd" docker build -t alpine-pd -f ./app/prod/Dockerfile ./app/prod

• Start up production services docker-compose -f docker-compose.prod.yml up

[fyliu]

@alexlaw528 I think the "alpine" is usually part of the image tags. Like -t pd:latest-alpine

I'm not sure if there's a best practice for managing dev and prod dockerfiles. I see some people do Dockerfile.prod, or use the same Dockerfile for both with conditionals. I guess putting it in a directory is as good as any. We can think about this later.

We should also do multistage build to maybe avoid part of the 211MB that system dependencies take up. This is just a note for a later issue.

[ExperimentsInHonesty]

• We are closing this and it's being replaced by #275