Handle CIQ Identities correctly

[gtback]

Fix #302

[gtback]

@clenk , @rpiazza : Can one of you take a look at this and merge if it fixes the problems you were having, and the CI build passes?

[rpiazza]

Ran a test - that idiom is still wrong.

@emmanvg seems to think it is some issue with getting the xsi:type set.

[clenk]

My problem may be unrelated - STIXPackage.from_xml() isn't reading in the Identity correctly and just creates a ta:Identity/ stub.

[clenk]

I believe my problem comes from IdentityType.buildchildren(), which does nothing if the NodeName_ == "Specification" which is true for a CIQIdentity. Should we do something like MalwareType.buildchildren(), which imports the proper extension module?

EDIT: Hmm, the CIQIdentity3_0InstanceType binding class has Specification, so maybe I'm barking up the wrong tree to suggest it be added to the default IdentityType.

[emmanvg]

Just pushed some changes. It should be working now. :)

[clenk]

This fixes the issue I was seeing.