Merge pull request #3 from hybridgroup/21-beaglebone-adaptor-servo

Fixes some bugs with setting up PWM on BBB automatically.
Use peerDependencies to pull in gpio and i2c drivers
Tests green when using Cylon.Adaptors.Adaptor base class
Update require cylon core version
Even simpler syntax
Merge pull request #4 from hybridgroup/derive-adaptor

Tests green when using Cylon.Adaptors.Adaptor base class
Update to 0.2.0
Fixes servo support to use dutyCycle 0.5ms to 2.5ms with a 50hz frequency.