[Fix] Fix pom missing attributes.

Author: zhanghai

bintray.gradle

@@ -29,6 +29,9 @@ install {
  repositories.mavenInstaller {
  pom {
  project {
+ groupId GROUP
+ artifactId project.name
+ version VERSION_NAME
  packaging 'aar'
  name project.name
  description POM_DESCRIPTION

gradle.properties

@@ -17,6 +17,7 @@ org.gradle.jvmargs=-Xmx1536m
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
 
+GROUP=me.zhanghai.android.retrofile
 VERSION_CODE=1
 VERSION_NAME=1.0.0