Add ingress controller unit tests

[sebrandon1]

Note: It looks like the Update() is fundamentally broken because it does not appear you can modify IngressController objects once they are created. I tried various things to try and get it to work.

I left my test in there but commented out until we decide what to do with the Update() function itself.

Other changes:

• Modified the Delete() function to set the object to nil and return to match other package(s) functionality.

Resolves: https://github.com/openshift-kni/eco-goinfra/issues/361

[sebrandon1]

Updated for the comments left.

I removed my commented out test for Update() but I'm pretty sure that function doesn't work still. Do we want to maybe address that in another PR?