Invalid tenant name in the dev doc

[jaiyalas]

Hi, I'm trying to run testing based on the guide doc. And I noticed that, the test cli-command for the test of simple signing demo, in the deployment-guide/DCCDeploymentGuide.md is invalid and I would get a complaint:

An error occurred in the signing-service: Tenant doesn't exist.

I did a quick review, and i believe this is due to the fact that, in the signing-service, the route to sign is actually fixed with TEST_TENANT_NAME (src), which is fixed to 'testing' instead of 'test'.

So, I think the simplest quick fix, without modifying other repos, would be using testing instead of test in that cli-command, as

curl --location 'http://localhost:4005/instance/testing/credentials/issue' ...

[jchartrand]

Thank you for catching that @jaiyalas ! I've duly updated the doc.