Adds tests for parsing single app attributes
Adds tests for parsing single app attributes

* memory
* instance count
* hostname
* domain
* stack
* buildpack
* command

[Finishes #62429132, #62429166, #62429184, #62429196, #62429286, #62429304, #62429334]

cloudfoundry/cli,cloudfoundry/cli,cloudfoundry/cli