Remove example keys as a best practice

[aaronpkahn]

Removing example keys, so that no one accidentally uses a shared example key. If a user generates their own key, at least it won't be a key others have access to.

[agbpatro]

https://github.com/teslamotors/fleet-telemetry/blob/main/Makefile#L47

change this to

integration: generate-certs
	@echo "** RUNNING INTEGRATION TESTS **"
	./test/integration/pretest.sh
	docker-compose -p app -f docker-compose.yml build
	docker-compose -p app -f docker-compose.yml up -d --remove-orphans
	./test/integration/test.sh
	docker-compose -p app -f docker-compose.yml down
	@echo "** INTEGRATION TESTS FINISHED **"