added BUILD_RESULT to environment variables

[azweb76]

We have a need to run a post build script for any build status, however we need to perform certain actions if the build is success, failed or any other status. By adding the build result as a BUILD_RESULT environment variable, we can run a single script for all build results and use logic do determine what we action to perform.

if [[ "$BUILD_RESULT" == "SUCCESS" ]]; then
  ./success_script.sh
else
  ./failed_script.sh
fi

[dheid]

Good idea! Thanks for your contribution!