Gradle release plugin error

Hi I am trying to use the gradle release plugin tool. I have the following code listed in my build.gradle but for some reason I am getting the following error. Can u tell me where I am going wrong?

FAILURE: Build failed with an exception.

  • Where: Build file ‘/Users/DEV/Tools/gradle-1.6/samples/java/quickstart/build.gradle’ line: 13

  • What went wrong: A problem occurred evaluating root project ‘quickstart’. > Unsupported SCM system, no .svn, .bzr, .git, or .hg found in [/Users/ncheruku/DEV/Tools/gradle-1.6/samples/java/quickstart] or its parent directories.

  • Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

which release plugin are you refering too?