title: Pick JenkinsFile from custom location in pipeline plugin of jenkins
body: <p>Can jenkins pipeline plugin pick jenkinsfile from a custom location and start the build?</p>
  
  <p>i don't want to keep jenkinsfile inside the source code. If there is any change in the source code. jenkinsfile from custom location should be picked and build should be started.</p>
  
  <p>Example:/home/test/jenkinsfile</p>