Support customization of line thickness

[vinaygopinath]

The thickness of the "completed" line (line leading to a completed step) and "not-completed" line (line leading to a not-completed step or the current step) is currently hardcoded in StepViewIndicator using setStrokeWidth.

    mNotCompletedLinePaint = new Paint();
    mCompletedLinePaint = new Paint();
    mNotCompletedLinePaint.setAntiAlias(true);
    mNotCompletedLinePaint.setColor(mNotCompletedLineColor);
    mNotCompletedLinePaint.setStyle(Paint.Style.STROKE);
    mNotCompletedLinePaint.setStrokeWidth(2);

    mCompletedLinePaint.setAntiAlias(true);
    mCompletedLinePaint.setColor(mCompletedLineColor);
    mCompletedLinePaint.setStyle(Paint.Style.STROKE);
    mCompletedLinePaint.setStrokeWidth(2);

Allowing the user to customize the stroke width of the completed and not-completed lines would be a nice enhancement.

What's required

1. Create new integer fields in StepViewIndicator: mCompletedLineThickness and mNotCompletedLineThickness, both of which should default to 2 (current thickness)
2. Create getters and setters for the new fields (Refer the getters and setters for circle radius and line length)
3. Expose the getters and setters on StepViewIndicator via StepView, which should simply call the methods on StepViewIndicator (Refer to the getters and setters for circle radius and line length in StepView)
4. Update the code copy-pasted above to use the new mCompletedLineThickness and mNotCompletedLineThickness

mNotCompletedLinePaint.setStrokeWidth(mNotCompletedLineThickness);
..
mCompletedLinePaint.setStrokeWidth(mCompletedLineThickness);

Please assign yourself and/or leave a comment if you decide to tackle this issue.