MS: update legislators with better data

[jessemortenson]

Fixes a bunch of retirements in MS.

This is the outcome of the improved script that handles addresses from the new data source. So far this is kind of a mixed bag: cleans up some addresses but loses some that were in there previously. I think that is a result of:

• MS legislator pages sometimes/often(?) include home addresses, which I have excluded from this output. But that might be the wrong decision.
• Don't have the "mailing" specific addresses yet, blocked by People: add distinct mailing classification options to offices openstates-core#120

Seems like I should just go ahead and merge since we need to fix the retirements

[jessemortenson]

@chris-erickson Here is a first PR that shows a full jurisdiction with those new office classifications

[chris-erickson]

Sounds good! Worst case our imports will break and I'll fix them 😆