Added simple dependency checks to all annotation processors

Change-Id: I8de5ca9a6e56bbcd32168cdb23474be4401171a7
diff --git a/t/annotation/dereko_struct.t b/t/annotation/dereko_struct.t
index 921b58e..73b5be2 100644
--- a/t/annotation/dereko_struct.t
+++ b/t/annotation/dereko_struct.t
@@ -3,6 +3,7 @@
 use warnings;
 use utf8;
 use Test::More;
+use KorAP::XML::Annotation::DeReKo::Structure;
 use lib 't/annotation';
 use TestInit;
 use Scalar::Util qw/weaken/;