Only execute examples on the latest scala version

Author: jakzal

.travis.yml

@@ -1,9 +1,12 @@
 language: scala
 sudo: false
 
-scala:
-   - 2.11.12
-   - 2.12.6
+matrix:
+  include:
+   - scala: 2.11
+   - scala: 2.12
+     env: EXECUTE_EXAMPLES=true
+  fast_finish: true
 
 cache:
   directories:
@@ -13,7 +16,10 @@ before_cache:
 - rm -rf $HOME/.m2/repository/io/cucumber
 
 before_install:
-- export MODULES_TO_RUN="scala/scala_"$(echo $TRAVIS_SCALA_VERSION | sed -e 's/\([0-9]*\.[0-9]*\)\..*/\1/')",examples" && echo $MODULES_TO_RUN
+- |
+  export MODULES_TO_RUN="scala/scala_"$(echo $TRAVIS_SCALA_VERSION | sed -e 's/\([0-9]*\.[0-9]*\)\..*/\1/')
+  [[ $EXECUTE_EXAMPLES = true ]] && export MODULES_TO_RUN=$MODULES_TO_RUN",examples"
+  echo $MODULES_TO_RUN
 
 install:
 - mvn install -pl $MODULES_TO_RUN -DskipTests=true -Dmaven.javadoc.skip=true -B -V