[tests] Fix some tests methods names.

tests/Predis/Command/KeyRenamePreserveTest.php

@@ -75,7 +75,7 @@ class KeyRenamePreserveTest extends PredisCommandTestCase
      * @expectedException \Predis\Response\ServerException
      * @expectedExceptionMessage ERR no such key
      */
-    public function testReturnsFalseOnNonExistingKeys()
+    public function testThrowsExceptionOnNonExistingKeys()
     {
         $redis = $this->getClient();
 

tests/Predis/Command/SetMembersTest.php

@@ -63,7 +63,7 @@ class SetMembersTest extends PredisCommandTestCase
     /**
      * @group connected
      */
-    public function testReturnsFalseOnNonExistingSet()
+    public function testReturnsEmptyArrayOnNonExistingSet()
     {
         $redis = $this->getClient();