fix(demo): correct apostrophe character

Author: javier-godoy

src/test/java/com/flowingcode/vaadin/addons/twincolgrid/BoundDemo.java

@@ -76,7 +76,7 @@ private void initializeData() {
     availableBooks.add(new Book("1478375108", "Vaadin Recipes"));
     availableBooks.add(new Book("9781849515221", "Learning Vaadin"));
     availableBooks
-        .add(new Book("9781782162261", "Vaadin 7 UI Design By Example: Beginner�s Guide"));
+        .add(new Book("9781782162261", "Vaadin 7 UI Design By Example: Beginner\u2019s Guide"));
     availableBooks.add(new Book("9781849518802", "Vaadin 7 Cookbook"));
     availableBooks.add(new Book("9526800605", "Book of Vaadin: 7th Edition, 1st Revision"));
     availableBooks.add(new Book("9789526800677", "Book of Vaadin: Volume 2 "));

src/test/java/com/flowingcode/vaadin/addons/twincolgrid/DragAndDropDemo.java

@@ -66,7 +66,7 @@ private void initializeData() {
     availableBooks.add(new Book("1478375108", "Vaadin Recipes"));
     availableBooks.add(new Book("9781849515221", "Learning Vaadin"));
     availableBooks
-        .add(new Book("9781782162261", "Vaadin 7 UI Design By Example: Beginner�s Guide"));
+        .add(new Book("9781782162261", "Vaadin 7 UI Design By Example: Beginner\u2019s Guide"));
     availableBooks.add(new Book("9781849518802", "Vaadin 7 Cookbook"));
     availableBooks.add(new Book("9526800605", "Book of Vaadin: 7th Edition, 1st Revision"));
     availableBooks.add(new Book("9789526800677", "Book of Vaadin: Volume 2 "));

src/test/java/com/flowingcode/vaadin/addons/twincolgrid/FilterableDemo.java

@@ -57,7 +57,7 @@ private void initializeData() {
     availableBooks.add(new Book("1478375108", "Vaadin Recipes"));
     availableBooks.add(new Book("9781849515221", "Learning Vaadin"));
     availableBooks
-        .add(new Book("9781782162261", "Vaadin 7 UI Design By Example: Beginner�s Guide"));
+        .add(new Book("9781782162261", "Vaadin 7 UI Design By Example: Beginner\u2019s Guide"));
     availableBooks.add(new Book("9781849518802", "Vaadin 7 Cookbook"));
     availableBooks.add(new Book("9526800605", "Book of Vaadin: 7th Edition, 1st Revision"));
     availableBooks.add(new Book("9789526800677", "Book of Vaadin: Volume 2 "));