Testing that when transposing in the key of C#, the 5th chord is transposed correctly (i.e. C-G-C becomes C#/G#/C#, not C#/Ab/C#).
Adding supplementary ii-V-I tests.
Testing that when trying to target an invalid minor key, we get the correct minor key instead. (I.e. if you try to transpose to Gbm, you should get F#m chords instead.)
Testing that when target a minor key which is noted as minor, we use the key generated by the chordParts method (otherwise, we end up with a strange bug).
Supplementary test for minor transposition to extreme enharmonic keys.