omg get error without specifying resource

[kevchu3]

Issue:

When a user executes omg get without specifying a resource, the error returned doesn't accurately describe that the user forgot to specify a resource. In earlier versions of omg, it simply returned no message at all, and in later versions, it returned no resources found in XXX namespace.

Expected results:

The oc get command returns the error You must specify the type of resource to get. Also, as we're planning to implement oc describe, this inconsistency in error message exists there as well. The oc describe command returns error: You must specify the type of resource to describe.

[kxr]

@kevchu3 thanks for pointing this out. Will fix it.