Add .gitlab-ci.yml

.gitlab-ci.yml

+# Build Icecast
+build:
+  tags:
+    - alpine
+    - docker
+
+  stage: build
+
+  before_script:
+  - apk update
+  - apk add musl-dev git make gcc automake autoconf libtool
+
+  script: 
+    # compile
+    - ./autogen.sh
+    - ./configure
+    - make
+    - make distcheck
+