Expose find-appointment endpoint on vets-api

[kjduensing]

Issue Description

Context

The service and client that integrate with the Travel Pay API have been written and tested. We need to expose an endpoint for SMOC and future use.

Impact

Allows completion of SMOC work

Endpoint Path

/travel_pay/v0/appointments?appt_datetime=1999-01-01T00:00:00Z

Response Schema

{
  appointmentId: UUID
}

Back end tasks

• [ ] ~Client code written - calls correct endpoint~
• [ ] ~Service code written - transforms/processes response from client~
  • [ ] ~Handle errors~
• [ ] Controller endpoint written
• [ ] Config
  • [ ] settings.test.yml updated if needed
  • [ ] settings.local.yml updated if needed
  • [ ] settings.yml updated if needed
  • [ ] infra-manifests updated if needed
  • [ ] dev
  • [ ] staging
  • [ ] prod
• [ ] Tests written
  • [ ] Unit
  • [ ] Happy path
  • [ ] Exhaustive failure paths
  • [ ] Integration
  • [ ] VCR Cassettes
  • [ ] Betamocks registration
• [ ] Mock data
• [ ] Testing
  • [ ] Unit tests pass
  • [ ] QA testing - try to break it in staging
• [ ] Improve 1 thing about the codebase
• [ ] Swagger docs updated

Acceptance Criteria

• [ ] Backend tasks complete
• [ ] I can hit the endpoint defined above using postman or another testing tool and see the response defined above

[kjduensing]

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