fix: have diana actually store api key in its credhub
fix: have diana actually store api key in its credhub

[#170059380](https://www.pivotaltracker.com/story/show/170059380)

Co-authored-by: Angela Chin <09c3fe443cd90255b3ab6945ab331bb5cdf11ccb@pivotal.io>

cloudfoundry-incubator/cf-routing-release,cloudfoundry-incubator/cf-routing-release,cloudfoundry-incubator/cf-routing-release