Remove legacy gnugen CI, add build instructions

.gitlab-ci.yml

@@ -1,68 +0,0 @@
-image: debian:buster
-stages:
-    - lint
-    - build
-    - checking
-    - deploy
-
-run-lint:
-  stage: lint
-  allow_failure: true
-  tags:
-    - debian
-  before_script:
-    - apt-get update
-    - apt-get install -y rubocop
-  script:
-    - rubocop
-
-# Build package using dpkg-buildpackage
-run-build:
-    stage: build
-    tags:
-        - debian
-        - generic
-    script:
-        - echo 'Acquire::http { Proxy "http://rapperswil:3142"; };' > /etc/apt/apt.conf.d/02proxy
-        - apt-get update -qy
-        - apt-get install -y dpkg-dev debhelper
-        - dpkg-buildpackage -us -uc
-        - mkdir build-artifacts
-        - mv ../mlmmj-ldap-sync_* build-artifacts/
-    artifacts:
-        paths:
-            - build-artifacts
-
-# Check built package using lintian.
-run-checking:
-    stage: checking
-    tags:
-        - debian
-        - generic
-    script:
-        - echo 'Acquire::http { Proxy "http://rapperswil:3142"; };' > /etc/apt/apt.conf.d/02proxy
-        - apt-get update -qy
-        - apt-get install -y lintian
-        - lintian -i build-artifacts/mlmmj-ldap-sync*.changes
-
-# Deploy the built package to rapperswil
-run-deploy:
-    stage: deploy
-    variables:
-    only:
-        - tags
-    tags:
-        - debian
-        - generic
-    before_script:
-        - 'which ssh-agent || (apt-get update -qy && apt-get install openssh-client -y)'
-        - eval $(ssh-agent -s)
-        - echo "$CD_SSH_PRIVATE_KEY" | tr -d '\r' | ssh-add - > /dev/null
-        - mkdir -p ~/.ssh
-        - echo "$CD_SSH_SERVER_HOSTKEYS" > ~/.ssh/known_hosts
-        - chmod 644 ~/.ssh/known_hosts
-    script:
-        - apt-get update -qy
-        - apt-get install -y dput
-        - 'echo "$CD_MINIDINSTALL_CONFIG" > ~/.dput.cf'
-        - 'dput -u gnugen build-artifacts/mlmmj-ldap-sync*.changes'

README.md

@@ -2,3 +2,5 @@
 
 Simple script to sync mailman3 lists with LDAP groups, forked from [GNU Generation's
 mlmmj-ldap-sync](https://gitlab.gnugen.ch/gnugen/mlmmj-ldap-sync).
+
+To build the DEB package, install `dpkg-dev` and `debhelper`, then run `dpkg-buildpackage -us -uc`.