Add heart rate feature

Full Changelog: v1.0.0...v1.0.1

New feature: heart rate calculation, the code for the signal processing can be found at heart_rate.js

Refactor: add octave.js which have all of ported octave functions (note that this is still incomplete and the implementations is slow and unstable)

First stable version is out !!!

Stable version1.0.0 has been released 🎉
The respiration rate calculation have around 85% accuracy based on some processing and analysis.
Also consist of so many functions that already ported from octave (including snr that is currently not available in octave yet), it also matches matlab mechanism specifically for findpeaks function.