3.0.0

• Migrate to Kotlin #21
• Refactor support lib to AndroidX #13
• Extract dependencies and configurations from build files #22
• Add numberkeyboard_ resource prefix #23 (breaking change)

Migration

Add the prefix numberkeyboard_ to all the library attributes and resources.
E.g.

Before:  keyboard:keyboardType="integer"
Now:     keyboard:numberkeyboard_keyboardType="integer"