title: How to publish android library without R and BuildConfig
body: <p>I made an android library publish it to jcenter for several versions. But when I use it, I found  R and BuildConfig reference from my own library.How to avoid upload R and BuildConfig.
  Here is my build.gradle:</p>
  
  <pre><code>version = "2.1.3"
  def siteUrl = 'https://github.com/boybeak/DelegateAdapter'
  def gitUrl = 'https://github.com/boybeak/DelegateAdapter.git'
  group = "com.github.boybeak"
  install {
      repositories.mavenInstaller {
          // This generates POM.xml with proper parameters
          pom {
              project {
                  packaging 'aar'
                  name 'DelegateAdapter'
                  url siteUrl
                  licenses {
                      license {
                          name 'Apache-2.0'
                          url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
                      }
                  }
                  developers {
                      developer {
                          id 'boybeak'
                          name 'gaoyunfei'
                          email 'boybeak@qq.com'
                      }
                  }
                  scm {
                      connection gitUrl
                      developerConnection gitUrl
                      url siteUrl
                  }
              }
          }
      }
  }
  
  task sourcesJar(type: Jar) {
      from android.sourceSets.main.java.srcDirs
      classifier = 'sources'
  
      exclude "**/R.class"
      exclude "**/BuildConfig.class"
  }
  
  task jar(type: Jar) {
      from 'build/intermediates/classes/release'
      exclude '**/BuildConfig.class'
      exclude '**/R.class'
  
  }
  
  task javadoc(type: Javadoc) {
      source = android.sourceSets.main.java.srcDirs
      classpath += project.files(android.getBootClasspath().join(File.pathSeparator))
      options.encoding "UTF-8"
      options.charSet 'UTF-8'
      failOnError false
  
      exclude "**/R.java"
      exclude "**/BuildConfig.java"
  }
  
  task javadocJar(type: Jar, dependsOn: javadoc) {
      classifier = 'javadoc'
      from javadoc.destinationDir
  
      exclude "**/R.java"
      exclude "**/BuildConfig.java"
  }
  
  artifacts {
      archives jar
      archives javadocJar
      archives sourcesJar
  }
  Properties properties = new Properties()
  properties.load(
      project.rootProject.file('local.properties').newDataInputStream()
  )
  bintray {
  
      user = properties.getProperty("bintray.user")
      key = properties.getProperty("bintray.apikey")
      configurations = ['archives']
      pkg {
          repo = "nulldreams"
          name = "adapter"                // project name in jcenter
          websiteUrl = siteUrl
          vcsUrl = gitUrl
          licenses = ["Apache-2.0"]
          publish = true
      }
  }
  </code></pre>