title: retrofit inside aar library not working, developing sdk java.lang.NoClassDefFoundError: Failed resolution of: Lretrofit2/Retrofit$Builder;
body: <p>developing sdk aar and integrate in app module.
  build type release not working app getting crash</p>
  <p>java.lang.NoClassDefFoundError: Failed resolution of: Lretrofit2/Retrofit$Builder;
  at com.kv.mylibrary2.ApiClient.getService(ApiClient.java:23)
  at com.kv.mylibrary2.EzeTap.(EzeTap.java:10)</p>
  <p>added -keep retrofit not working.
  retrofit inside app module direct working, from sdk not working</p>