Update app.py

app.py

@@ -13,13 +13,13 @@ cache.update()
 cache.open()
 pkg = cache[pkg_name]
 if pkg.is_installed:
-    print "{pkg_name} already installed".format(pkg_name=pkg_name)
+    print ("{pkg_name} already installed".format(pkg_name=pkg_name))
 else:
     pkg.mark_install()
     try:
         cache.commit()
     except Exception, arg:
-        print >> sys.stderr, "Sorry, package installation failed [{err}]".format(err=str(arg))
+        print (sys.stderr, "Sorry, package installation failed [{err}]".format(err=str(arg)))
 # from xvfbwrapper import Xvfb
 # vdisplay = Xvfb()
 # vdisplay.start()