Update Logger to be a Service that Talks to Stackdriver

[sethicis]

Description

Currently all "logging" in the app is handled via the Go standard "log" library.

This request is for the creation of a separate logger package that will utilize GCP's stackdriver Go library. It will expose methods for logging warning, info, and critical messages.

Go Stackdriver library: https://cloud.google.com/logging/docs/setup/go

Implementation Details

• [ ] Define a logger interface to make swapping out the logger service easier.
• [ ] Create a new package for the logger service that wraps the Go Stackdriver library.
• [ ] Replace all the usages of Go Standard "Log" Library with the new logger service.