Adding gitlab ci config file

.gitlab-ci.yml

+image: mono:latest
+
+stages:
+    - test
+    - build
+
+before_script:     
+    - nuget restore -NonInteractive
+
+release:
+    stage: build
+    only:
+        - master
+    artifacts:
+        paths:
+          - build/release/
+    script:
+        - msbuild "MyProject.sln" /p:Configuration="Release" /p:Platform="Any CPU" /p:OutputPath="build/release/"
+    
+debug:
+    stage: test
+    script:
+        - msbuild "MyProject.sln" /p:Configuration="Debug" /p:Platform="Any CPU" /p:OutputPath="build/debug/"
+        - mono packages/NUnit.ConsoleRunner.3.6.0/tools/nunit3-console.exe build/debug/MyProject.Test.dll
\ No newline at end of file