chore(Example): add deploy script

Author: Marco Cesarato

Example/package.json

@@ -1,6 +1,9 @@
 {
 	"main": "node_modules/expo/AppEntry.js",
+	"homepage": "https://marcocesarato.github.io/react-native-input-spinner/",
 	"scripts": {
+		"deploy": "gh-pages -d web-build",
+		"predeploy": "expo build:web",
 		"start": "expo start",
 		"android": "expo start --android",
 		"ios": "expo start --ios",
@@ -17,7 +20,8 @@
 		"react-native-web": "~0.15.0"
 	},
 	"devDependencies": {
-		"babel-preset-expo": "8.3.0"
+		"babel-preset-expo": "8.3.0",
+		"gh-pages": "^3.1.0"
 	},
 	"private": true
 }