Replace httpbin in integration tests with different application

[barchw]

Description

Running httpbin as a target for integration and performance tests provides a huge overhead in terms of startup and response bottleneck. Replacing it with an application that could handle the traffic and startup better would allow us to get more meaningful results from performance tests, as well as decrease the time that integration tests take.

Reasons

• Httpbin startup takes a long time
• We don't use the full capabilities of httpbin application
• Httpbin memory and cpu load hits maximum during performance tests and the autoscaling does not compensate for this, meaning that the tests don't test our setup limits, but httpbin limits instead

DoD:

• Agree on a different application for target
  • Consider using https://github.com/werdes72/gofihttpbin
• Perfomance tests use new implementation:
  • New application is used
  • Make sure that mem and CPU aren't maxing out
• Integration tests use new implementation

Follow up(s)

• Consider setting up thresholds for performance tests and inform on internal slack when threshold is breached
• Allow running more sophisticated scenarios (e.g. testing JWT scenarios with provider number > 50)