Gap size changing

[AlmazKh]

Description

• Feature request Change mSelectorTextGapHeight (gap height) #69
• Added np_gapSize attribute for NumberPicker view. Using this attr you can change width/height between picker items

Demo

Below in the screenshot you can see an example of using different gap size

First NumberPicker uses default gap size. View in the middle uses gap size -50. Last one uses gap size 50

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings