Use https for doc view url.

Updated Doc test for the new updated url.

Author: kevzlou7979

src/main/java/gwt/material/design/addins/client/docviewer/MaterialDocViewer.java

@@ -64,7 +64,7 @@ public MaterialDocViewer(String url) {
     @Override
     protected void onLoad() {
         super.onLoad();
-        getElement().setAttribute("src", "http://docs.google.com/gview?url=" + url + "&embedded=" + embedded);
+        getElement().setAttribute("src", "https://docs.google.com/gview?url=" + url + "&embedded=" + embedded);
     }
 
     /**

src/test/java/gwt/material/design/addins/client/MaterialDocViewerTest.java

@@ -43,10 +43,10 @@ protected <T extends MaterialDocViewer> void checkUrl(T docViewer) {
         assertEquals(docViewer.getUrl(), URL);
         assertTrue(docViewer.getElement().hasAttribute("src"));
         docViewer.setEmbedded(true);
-        assertEquals(docViewer.getElement().getAttribute("src"), "http://docs.google.com/gview?url=someurl&embedded=true");
+        assertEquals(docViewer.getElement().getAttribute("src"), "https://docs.google.com/gview?url=someurl&embedded=true");
         docViewer.setEmbedded(false);
         docViewer.removeFromParent();
         RootPanel.get().add(docViewer);
-        assertEquals(docViewer.getElement().getAttribute("src"), "http://docs.google.com/gview?url=someurl&embedded=false");
+        assertEquals(docViewer.getElement().getAttribute("src"), "https://docs.google.com/gview?url=someurl&embedded=false");
     }
 }