Fix examples and phpspec definition for Twig 3

.gitignore

@@ -1,2 +1,4 @@
 bin
-vendor
+vendor
+composer.lock
+.phpunit.cache/

examples/basic.php

@@ -2,12 +2,12 @@
 
 require __DIR__.'/../vendor/autoload.php';
 
-$loader = new Twig_Loader_Array(array(
+$loader = new Twig\Loader\ArrayLoader(array(
     'uniqid' => 'Hi, I am unique: {{ php_uniqid() }}.',
     'floor'  => 'And {{ php_floor(7.7) }} is floor of 7.7.',
 ));
 
-$twig = new Twig_Environment($loader);
+$twig = new Twig\Environment($loader);
 $twig->addExtension(new Umpirsky\Twig\Extension\PhpFunctionExtension());
 
 echo $twig->render('uniqid') . PHP_EOL;

spec/Umpirsky/Twig/Extension/PhpFunctionExtensionSpec.php

@@ -3,17 +3,18 @@
 namespace spec\Umpirsky\Twig\Extension;
 
 use PhpSpec\ObjectBehavior;
-use Prophecy\Argument;
+use Twig\Extension\AbstractExtension;
+use Umpirsky\Twig\Extension\PhpFunctionExtension;
 
 class PhpFunctionExtensionSpec extends ObjectBehavior
 {
     function it_is_initializable()
     {
-        $this->shouldHaveType('Umpirsky\Twig\Extension\PhpFunctionExtension');
+        $this->shouldHaveType(PhpFunctionExtension::class);
     }
 
     function it_is_a_Twig_extension()
     {
-        $this->shouldHaveType('Twig_Extension');
+        $this->shouldHaveType(AbstractExtension::class);
     }
 }