title: pipelines and release vs snapshot builds
body: <p>I want to use jenkins pipelines for continuous integration, but not cd, I am still using the snapshot and release model of maven.
  How to cause the pipeline to execute a release build or a snapshot build depending on some condition?
  Also, how do you trigger some things like testing on other platforms, integration tests, etc only sometimes? I do not want long tests and resource hungry booting on windows to go each time I commit.</p>