KAZOO-1628: add system error for lacking credit
KAZOO-1620: move billing piece to when transitioning to COMPLETED
KAZOO-1620: formatting
KAZOO-1620: cleanup
KAZOO-1628: start a transaction
KAZOO-1620: formatting
KAZOO-1628: search port requests for number lookups
KAZOO-1626: convert states to macros

if number isn't in numbers db, check the port_requests db
KAZOO-1626: more macro-izing
KAZOO-1626: return the right error tuple
KAZOO-1626: cleaned up logging
KAZOO-1620: normalize port numbers to E164
KAZOO-1626: refactor to sub functions, and return port error appropriately