Add .gitlab-ci.yml

.gitlab-ci.yml

+before_script:
+  - apt-get update -qq
+  - apt-get install -qq build-essential curl git
+  - curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain nightly
+  - source "$HOME/.cargo/env"
+
+nightly:
+  script:
+    - cargo build
+    - cargo test
\ No newline at end of file