The ECG reader

A list gives the times, in seconds, of the R peaks of an ECG. You will find the gaps between them, the heart rate, and whether the rhythm is regular.

The idea. The heart rate in beats a minute is $60$ divided by the average time between two beats. The rhythm is regular if every gap is close to the average.

Your tasks.

1. Finish gaps. It gives the list of the times between neighbouring peaks.
2. Finish heart_rate. It gives the heart rate, rounded to a whole number.
3. Finish is_regular. It gives True if every gap is within $0.1$ s of the average gap.