Round beats per second tempo to beats per minute (fix mtest on Windows)

On Linux and on Windows double values of tempo for human-performed MIDI files appeared to be slightly different due to different results of beat detection (very small difference). 

In mtest win tempo = 2.1921, linux tempo = 2.1923 that was saved in compared score and lead to test failure.

I think that change bps double tempo value to rounded bpm [qRound(bps * 60.0) / 60.0] = 2.2 in example above is resounable.