Merge branch '19-improve-tiles-shuffling' into 'master'

Resolve "Improve tiles shuffling"

Closes #19

See merge request !17

android/gradle.properties

 org.gradle.jvmargs=-Xmx1536M
 android.useAndroidX=true
 android.enableJetifier=true
-app.versionName=0.0.12
-app.versionCode=12
+app.versionName=0.0.13
+app.versionCode=13

lib/screens/home.dart

@@ -148,7 +148,7 @@ class Home extends StatelessWidget {
     var random = new Random();
     int tilesCount = tiles.length;
 
-    for (int i = 0; i < 40; i++) {
+    for (int i = 0; i < (10 * tilesCount); i++) {
       int indexTile1 = random.nextInt(tilesCount);
       int indexTile2 = random.nextInt(tilesCount);