remove reset methods that do nothing?

[pixelzoom]

Related to #2 (code review).

There are a number of reset methods that do nothing, and are not called anywhere.

For example, AmpPhaseAccordionBox.js:

    /**
     * @public
     */
    reset() {
      // NO-OP
    }

This isn't hurting anything. But in cases where reset (or some other method) does nothing, PhET typically does not implement the method.

[Hyodar]

Removed both reset and step methods that did nothing.

[Hyodar]

Following the issues workflow: Assigning @pixelzoom for review.

[pixelzoom]

👍 closing.