Added CI configuration

Signed-off-by: Louis Vallat <louis@louis-vallat.xyz>

.gitlab-ci.yml

@@ -0,0 +1,45 @@
+default:
+  image: rust
+
+stages:
+  - build
+
+day-1:
+  stage: build
+  script:
+    - cd day1; cargo run --release ./input
+
+day-2:
+  stage: build
+  script:
+    - cd day2; cargo run --release ./input
+
+day-3:
+  stage: build
+  script:
+    - cd day3; cargo run --release ./input
+
+day-4:
+  stage: build
+  script:
+    - cd day4; cargo run --release ./input
+
+day-5:
+  stage: build
+  script:
+    - cd day5; cargo run --release ./input
+
+day-6:
+  stage: build
+  script:
+    - cd day6; cargo run --release ./input
+
+day-7:
+  stage: build
+  script:
+    - cd day7; cargo run --release ./input
+
+day-8:
+  stage: build
+  script:
+    - cd day8; cargo run --release ./input