BRIDGE-860 E2E Tests of Swagger Def

# Summary

This adds E2E tests for testing the new swagger new endpoint `/dev/v0/payables/rtps/{rtp}/atps'

# Test Plan

* Run All tests
* Run E2E: get All ATPs 

Test Results

```

 E2E: get All ATPs
    objectID tests

      1) with a valid objectID

      ✓ objectID with an invalid pattern

      ✓ objectID is too short

      ✓ objectID is too long

      ✓ responds with 404

      ✓ responds with error body

      ✓ responds with error body (58ms)


  6 passing (701ms)
  1 failing

  1) E2E: get All ATPs
       objectID tests
         with a valid objectID:
     Error: expected 502 "Bad Gateway", got 500 "Internal Server Error"

```