Only include the authority name when compiling the agent sha1 hash

@lcdhoffman we're looking at the task https://www.pivotaltracker.com/story/show/64190548

We were hoping to piggy back on your agent sha1 to test for duplicates of the authority name.  I've tweaked the generate of the hash to only include the authorized name, which mostly satisfies our requirement and hopefully doesn't break yours. 

Our requirement implies an agent is unique based on the hash of its authority name alone.  Would it be wrong to scale back the sha1 to only include the authority name fields?  It would the nice if the import duplication rules matched those in staff interface.

As it stands, I don't think this PR is ready for merge and maybe requires further discussion, but let me know if you think we should pursue changing the hash as described.