changed gitlab-ci configuration to use artifacts

.gitlab-ci.yml

 ---
 image: mathiwr/amdis-base:debian9
 
-cache:
-  key: "$CI_BUILD_REF_NAME"
-  untracked: true
-  paths:
-  - install/
-
 stages:
   - build
   - demo
@@ -18,6 +12,11 @@ build:9-debug-gcc:
   stage: build
   script:
   - tools/build_amdis.sh --stage build --config Debug
+  artifacts:
+    paths:
+    - install/
+    name: "$CI_BUILD_NAME"
+    expire_in: 6 hrs
   only:
   - master
 
@@ -25,6 +24,11 @@ build:9-release-gcc:
   stage: build
   script:
   - tools/build_amdis.sh --stage build --config Release
+  artifacts:
+    paths:
+    - install/
+    name: "$CI_BUILD_NAME"
+    expire_in: 6 hrs
   only:
   - master
 
@@ -32,6 +36,11 @@ build:9-parallel-debug-gcc:
   stage: build
   script:
   - tools/build_amdis.sh --stage build --config Debug --parallel
+  artifacts:
+    paths:
+    - install/
+    name: "$CI_BUILD_NAME"
+    expire_in: 6 hrs
   only:
   - master
 
@@ -39,6 +48,11 @@ build:9-parallel-release-gcc:
   stage: build
   script:
   - tools/build_amdis.sh --stage build --config Release --parallel
+  artifacts:
+    paths:
+    - install/
+    name: "$CI_BUILD_NAME"
+    expire_in: 6 hrs
   only:
   - master