JENKINS-22293
java.lang.NoSuchMethodError: hudson.plugins.rake.Rake.<init>

Problem fixed based on gist from @felixbuenemann: https://gist.github.com/felixbuenemann/10261743
Ignore IDEA IntelliJ project files
simplifying pom structure and bumping up jenkins dependency to version 1.532.3 to make the build pass through
Replace deprecated org.codehaus.plexus.util.StringOutputStream with ByteArrayOutputStream (to fix the failing build)
Merge pull request #18 from pkuczynski/JENKINS-22293

Fix for JENKINS-22293