Changes to Speaker Example Sketch

This fixes the noisy tone issue #193
Tone interrupt collides with our interrupt, noisy tone is the result, and likely bad BPM values.

In order to fix this problem and use tone() the Arduino core needs to be updated so that the tone library operates 'hands free' like the PWM library. Or, the PWM library needs to be updated to accept a frequency parameter to ensure a clean(er) note. There are some architectures upon which the Tone library might work: nRF52? ESP32?

Clarified which libraries to use in ESP32 example

fixed bug that prevented use of servo

Had to chase down places where servo.h was tested

Fixed bug when using Arduino Servo library

There was a conflict arising from multiple use of timer between PulseSensor and Servo.
Used the __has_include conditional to solve it.

Merge pull request #191 from WorldFamousElectronics/Version-2.0-Beta

Version 2.0.0

Merge pull request #182 from WorldFamousElectronics/joel-m-branch-1

Support for Arduino DUE

Merge pull request #180 from biomurph/master

Arduino UNO R4 LED Matrix Examples

Merge pull request #179 from biomurph/master

Adding support for UNO R5

Merge pull request #178 from biomurph/master

bug fix in PTT and interrupts

Merge pull request #176 from biomurph/master

version bump