Include repo topics and app data in exported metadata

[MattIPv4]

Description

Update the GitHub scraping logic to include all topics a repo has, as well as the app data for PRs & users.

Adding the custom DB logic to the export allows a dev to remotely export the final JSON on their local device, connecting to the remote prod/staging DB.

E.g. docker-compose exec -e HACKTOBERFEST_DATABASE_HOST=the.hacktoberfest.staging.fqdn -e HACKTOBERFEST_DATABASE_PORT=12345 -e HACKTOBERFEST_DATABASE_NAME=default -e HACKTOBERFEST_DATABASE_USERNAME=dodge -e HACKTOBERFEST_DATABASE_PASSWORD=hunter2 -e HACKTOBERFEST_DATABASE_TIMEOUT=10 -e HACKTOBERFEST_DATABASE_CUSTOM=1 app bundle exec rake export:user_stats

Test process

• bundle exec rake github:import_metadata
• Allow time for jobs to run
• Check data entries in repo_stats table, should include topics key
• Check data entries in pr_stats table, should include app key
• Check data entries in user_stats table, should include app key

Requirements to merge

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code in hard-to-understand areas
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[MattIPv4]

@katjuell this should be good to go now, including exporting locally from a remote DB.