Added Docker and email transmission setup, corrected tests

[this-Aditya]

This PR:

• Adds the Docker setup for appserver microservices.
• Adds support for email notification transmission for the appserver Jersey and cloud-messaging microservice.
• Fixes failing integration tests for the appserver Jersey.

[dosubot]

Related Documentation

1 document(s) may need updating based on files changed in this PR:

RADAR-base's Space

• Notification System

^{How did I do? Any feedback?}  

[this-Aditya]

One commit in this PR contains the non encrypted google-application-credentials.json file, which I was using for testing and has been deleted. This file will no longer work as I have revoked it, but it poses no harm being present in the previous commit. I am mentioning this because GitHub may issue a warning when merging the PR.