Styling Options

Adds following styling attributes:

• app: dropsySelector
• app: dropsyBorderSelector
• app: dropsyLabelColor
• app: dropsyValueColor

Dropdown with basic features

Supports following:

• Listener setItemClickListener
• Elevation app:dropsyElevation (xml attr)
• Label app:dropsyLabel (xml attr)
• Dropdown Items app:dropsyItems (xml attr)