Rotate all API keys after Heroku security breach

[maxwofford]

Part of hackclub/hackclub#1767

These tokens need to be rotated:

• AIRTABLE_KEY
• ATHUL_AUTH_TOKEN
• BUGSNAG_API_KEY
• CLOUD9_ACCESS_TOKEN
• CLOUD9_PASSWORD
• CLOUD9_TEAM_NAME
• DATABASE_URL
• GIPHY_API_KEY
• GITHUB_BOT_ACCESS_TOKEN
• GOOGLE_MAPS_API_KEY
• GUGGY_API_KEY
• HACKATHONS_SITE_REBUILD_HOOK
• HEROKU_POSTGRESQL_GOLD_URL
• MLH_LHD_API_KEY
• MODE_URL
• NUMERACY_URL
• REDIS_TLS_URL
• REDIS_URL
• S3_ACCESS_KEY_ID
• S3_SECRET_ACCESS_KEY
• SEGMENT_URL
• SEGMENT_WRITE_KEY
• SENTRY_DSN
• SIDEKIQ_HTTP_PASSWORD
• SKYLIGHT_AUTHENTICATION
• SLACK_ADMIN_ACCESS_TOKEN
• SLACK_ADMIN_PASSWORD
• SLACK_CLIENT_ID
• SLACK_CLIENT_SECRET
• SMTP_PASSWORD
• SMTP_USERNAME
• STREAK_API_KEY
• STRIPE_SECRET_KEY
• TWILIO_ACCOUNT_SID
• TWILIO_API_KEY
• ZAPIER_URL