Upgrade to db2

[Powersource]

we have a main PR and then some followup issues

• Upgrade to db2 #96
• Add poBox functions ssb-box2#34
• Migrate old keyring to new box2 keyring #97
• Add noDb arg to testbot #98
• Test DMing a po-box if we don't do that already #99
• Re-enable ownKeys.list and ownKeys.register #100
• We're not slipping in our own DM key into recps anymore, keep an eye out for breakage #101
• Move unbox vectors into envelope-js/-spec #102
• Try removing the 10 sec sbot close time in the testbot helper #103 Remove 10sec timeout on testbot close #104

[Powersource]

start with a call between jacob and mix

[Powersource]

maybe prioritize #102 so we don't forget the context immediately