Update CI tests to directly use cpan packages (= use setup instructions

from README)

.gitlab-ci.yml

@@ -6,29 +6,14 @@ stages:
 test-perl:
   stage: test
   tags: [ debian ]
-  image: debian:stable
+  image: fedora:stable
   before_script:
-    - apt-get update
-    - >
-      apt-get -y install
-      libdancer-perl
-      libdancer-session-cookie-perl
-      libdancer-plugin-flashmessage-perl
-      libdbd-sqlite3-perl
-      libdbi-perl
-      libemail-sender-perl
-      libemail-simple-perl
-      libemail-valid-perl
-      libjson-perl
-      libnet-ldap-perl
-      libplack-perl
-      libtemplate-perl
-      liburi-perl
-      libyaml-perl
-      make
-      perl
-  script:
+    - dnf install -y perl-App-cpanminus make
     - perl Makefile.PL
+    - cpanm install ExtUtils::MakeMaker Module::CPANfile CPAN::Meta
+    - ./generate-cpanfile.pl
+    - cpanm --installdeps .
+  script:
     - cp config.example.yml config.yml
     - make test