Add .gitlab-ci.yml

.gitlab-ci.yml

+image: localhost:5000/ubuntu_gcc
+#before_script:
+#  - apt-get update
+#  - apt-get -y install cmake g++-7 gcovr bc
+#  - apt-get -y upgrade
+
+cache:
+  key: "$CI_COMMIT_REF_SLUG"
+  paths:
+    - build/
+  untracked: true
+
+stages:
+  - build
+  - test
+
+build:
+  stage: build
+  script:
+    - mkdir -p build
+    - cd build
+    - CXX=g++-7 CC=gcc-7 cmake .. -DCMAKE_BUILD_TYPE=Coverage
+    - make pastis
+
+test:
+  stage: test
+  script:
+    - ls > /dev/null # seems necessary to ensure build is here...
+    - cd build
+    - make unit_tests
+    - make coverage-report