Fixed custom pin constructor

Changes

This release just fixes a bug with the alternate constructor for custom pinout.
For instance:

CheapStepper stepper(2,3,4,5);   // use pins 2,3,4,5

works now as expected.

Initial Arduino Library Manager Release

CheapStepper v0.2 supports:

• 28BYJ-48 stepper motor/ULN2003 board + Arduino (any chip) + independent 5V power source
• use any 4 GPIO pins
• 8-phase half-stepping for 4096 mini-steps per shaft rotation
• total mini-steps customizable, e.g. to 4076 (for measured 63.68395:1 internal motor gear ratio)
• adjustable RPM with safety limit checks
• non-blocking moves (e.g. newMove(...) along with run() to perform moves across loop() iterations)
• blocking moves (move(...) pauses loop() while moving)
• direct mini-step control (step(...))
• API to poll stepper move status (e.g getStep(), getRpm(), getStepsLeft(), getDelay()...)
• 5V power source

3 annotated example sketches to illustrate non-blocking moves, blocking moves, and direct step control.

current roadmap

• acceleration/de-acceleration
• support for >5v power supply