Bug fix (figured bass): deceptive cadence

Two bugs:

segment.py: more strictness is identifying deceptive cadences - mainly that the first chord must be dominant-type

resolution.py: V-VI in a minor key forgot about the bass (code complains it can't find a solution)
Update (figured bass): descending 6/3 sequence

Added an new resolution from a minor to diminished triad (found in chromatic textures)
Feature (figured bass): V(7)-I7

Sometimes the composer will delay the leading tone resolution so that we get (at least temporarily) a V(7)–I7. Such a progression may also appear in an extended seventh sequence of descending fifths.

To do: add support for minor triad (sus7) resolution