fix: vertical alignment issues and warnings

Cloeses: #37

Author: Marco Cesarato

src/InputSpinner.js

@@ -945,7 +945,6 @@ class InputSpinner extends Component {
 				fontSize: this.props.buttonFontSize,
 				fontFamily: this.props.buttonFontFamily,
 				lineHeight: this.props.height,
-				verticalAlign: "middle",
 			},
 		];
 	}

src/Style.js

@@ -52,11 +52,16 @@ export const Style = StyleSheet.create({
 	buttonText: {
 		color: "white",
 		textAlign: "center",
+		justifyContent: "center",
+		alignItems: "center",
+		textAlignVertical: "center",
 	},
 	numberText: {
 		flex: 1,
 		textAlign: "center",
 		justifyContent: "center",
+		alignItems: "center",
+		textAlignVertical: "center",
 		borderWidth: 0,
 		...Platform.select({
 			web: {