[3.0] Strip FQDN period from the end of the domain

As brought up in #229 we're already treating all domains as absolute,
so adding direct support for it is a small bug fix. That said, fully
support for search domains requires a different handling of this and
will be done in a different PR.

Author: WyriHaximus

src/Resolver/Resolver.php

@@ -28,6 +28,7 @@ public function resolve($domain)
 
     public function resolveAll($domain, $type)
     {
+        $domain = trim($domain, '.');
         $query = new Query($domain, $type, Message::CLASS_IN);
 
         return $this->executor->query(

tests/FunctionalResolverTest.php

@@ -48,6 +48,17 @@ public function testResolveGoogleResolves()
         Loop::run();
     }
 
+    /**
+     * @group internet
+     */
+    public function testResolveGoogleFQDNResolves()
+    {
+        $promise = $this->resolver->resolve('google.com.');
+        $promise->then($this->expectCallableOnce(), $this->expectCallableNever());
+
+        Loop::run();
+    }
+
     /**
      * @group internet
      */