Verify that registration worked

[JoshKarpel]

At the end of register.py, once we have the token, we should verify that we can actually use it by doing a query against the HT Pheno collector and asserting that we show up in it.

(This is why we needed #21 )

[JoshKarpel]

Looks like Jason has implemented this in HTPhenotyping/execute_node_config#13 . Should we move it into the registration script? If we do, I'd like to get it set up in a way where we confirm that we can actually use the token we just created, not necessarily just that we can talk to htpheno-cm.