Add unzip requirement

Change-Id: I957e19257f7be8e2840d80a2abbec8b39dbc060c
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 25778fd..3468d25 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -23,6 +23,8 @@
       - uses: actions/checkout@v2
       - name: perl -V
         run: perl -V
+      - name: apt install unzip
+        run: perl -V
       - name: Install dependencies
         run: |
           cpanm --installdeps .
diff --git a/t/script/archive_tar_tempextract.t b/t/script/archive_tar_tempextract.t
index 7957029..60c2eac 100644
--- a/t/script/archive_tar_tempextract.t
+++ b/t/script/archive_tar_tempextract.t
@@ -19,6 +19,10 @@
   plan skip_all => 'Skip script tests';
 };
 
+unless (KorAP::XML::Archive::test_unzip) {
+  plan skip_all => 'unzip not found';
+};
+
 my $f = dirname(__FILE__);
 my $script = catfile($f, '..', '..', 'script', 'korapxml2krill');
 
diff --git a/t/script/serial.t b/t/script/serial.t
index a4a64f1..00e5559 100644
--- a/t/script/serial.t
+++ b/t/script/serial.t
@@ -5,11 +5,16 @@
 use File::Basename 'dirname';
 use File::Spec::Functions qw/catdir catfile/;
 use File::Temp qw/:POSIX/;
+use KorAP::XML::Archive;
 
 if ($ENV{SKIP_SCRIPT}) {
   plan skip_all => 'Skip script tests';
 };
 
+unless (KorAP::XML::Archive::test_unzip) {
+  plan skip_all => 'unzip not found';
+};
+
 my $f = dirname(__FILE__);
 my $script = catfile($f, '..', '..', 'script', 'korapxml2krill');