Additional integration tests for cf curl
Additional integration tests for cf curl

Notably, test the behavior of CF_TRACE when it is set to a file.

[Finishes #162431844]

Signed-off-by: Will Murphy <a0e419adf8e2224ae039ba5f1877fb7f62d300e5@pivotal.io>

cloudfoundry/cli,cloudfoundry/cli,cloudfoundry/cli