Tempo Parsing in MusicXML: Ignored BPM?

[mimbres]

First of all, thanks for sharing the great library. Usually, BPM is not always included in MusicXML files, but many of them do contain it, and it’s likely to be one of the following three:

1. From the <metronome> tag's <per-minute> value.
2. From the <direction> tag with the text format 'c. [number]' inside the <words> tag.
3. From the <sound> tag's <tempo> attribute.

Currently, it seems like these aren't being read as Tempo when loading the MusicXML file. Is it intentional that the BPM written in the score is being ignored? I think it would be more appropriate to load them into score.Tempo, so that it can be used when saving as MIDI. #340