bug: Bring staticnode up-to-date with tokenserver storage

[jrconlin]

• Add node & key_changed_at fields to staticnode db.
• add **kw to capture other unused args.

Closes #191

[jrconlin]

Hrm, I'm not sure about this, it seems like it might risk just masking future errors rather than failing loudly with a signature mismatch, and having them surface only later as incorrect data written into the db. @jrconlin thoughts?

I view the StaticNode to be kind of a special case. I'll note that we had already added the node and key_changed_at columns and had not checked StaticNode to see it was broken. Being a bit forgiving regarding extra arguments we're going to ignore anyway just means less future breakage.

Existins users of this codebase will need to run a db migration to get the new fields, will the existing migration from the tokenserver codebase work correctly here?

I see that the tokenserver migrations include both of those fields, so I presume that if the migration process works correctly, the table would have already been changed.

[jrconlin]

sigh. looks like the migration script does not fire automatically. Wohlraj is correct.

I'll see if I can work out what's going on with alembic or at least add instructions to existing syncstorage users.