Added CI example for Scala and SBT

doc/ci/examples/README.md

@@ -4,6 +4,7 @@
 - [Test and deploy a Ruby application to Heroku](test-and-deploy-ruby-application-to-heroku.md)
 - [Test and deploy a Python application to Heroku](test-and-deploy-python-application-to-heroku.md)
 - [Test a Clojure application](test-clojure-application.md)
+- [Test a Scala application](test-scala-application.md)
 - [Using `dpl` as deployment tool](deployment/README.md)
 - Help your favorite programming language and GitLab by sending a merge request
   with a guide for that language.

doc/ci/examples/test-scala-application.md

+## Test a Scala application
+
+This example demonstrates the integration of Gitlab CI with Scala applications using SBT. Checkout the example [project](https://gitlab.com/jasperdenkers/scala-sbt-sample-app) and [build status](https://gitlab.com/jasperdenkers/scala-sbt-sample-app/builds).
+
+### Add `.gitlab-ci.yml` file to project
+
+The following `.gitlab-ci.yml` should be added in the root of your repository to trigger CI:
+
+```yaml
+before_script:
+  # Install SBT
+  - echo "deb http://dl.bintray.com/sbt/debian /" | tee -a /etc/apt/sources.list.d/sbt.list
+  - apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 642AC823
+  - apt-get update -y
+  - apt-get install sbt -y
+  - sbt sbt-version
+
+test:
+  script:
+    - sbt clean coverage test coverageReport
+```
+
+The `before_script` installs [SBT](http://www.scala-sbt.org/) and displays the version that is being used. The `test` stage executes SBT to compile and test the project. [scoverage](https://github.com/scoverage/sbt-scoverage) is used as a SBT plugin to measure test coverage.
+
+You can use other versions of Scala and SBT by defining them in `build.sbt`.
+
+### Display test coverage in build
+Add the `Coverage was \[\d+.\d+\%\]` regular expression in the `Continuous Integration > Test coverage parsing` project setting to retrieve the test coverage rate from the build trace and have it displayed with your builds.