Add support for .cfignore file

In cloud foundry documentation https://docs.cloudfoundry.org/devguide/deploy-apps/prepare-to-deploy.html we can find following sentence:

"By default, when you push an application, all files in the application’s project directory tree are uploaded to your Cloud Foundry instance, except version control or configuration files with the following file extensions:

.cfignore

...."
It will be great if gradle plugin also interpret properly .cfignore file content.

先查看 issue 中链接的 Cloud Foundry 部署文档，然后检查 Gradle plugin 对应用程序上传和文件排除的处理。确定 ignore 文件在哪里处理，并验证项目的 .cfignore 规则会影响上传的文件；该 issue 未提供具体的源文件或要运行的测试。