[ci] Enable tests on ROCm 2.8 (#1482)

hipamd/Jenkinsfile

@@ -295,13 +295,13 @@ def docker_upload_dockerhub( String local_org, String image_name, String remote_
 String build_config = 'Release'
 String job_name = env.JOB_NAME.toLowerCase( )
 
-// The following launches 3 builds in parallel: rocm-head, rocm-2.7.x and cuda-10.x
-parallel rocm_2_7:
+// The following launches 3 builds in parallel: rocm-head, rocm-2.8.x and cuda-10.x
+parallel rocm_2_8:
 {
   node('hip-rocm')
   {
-    String hcc_ver = 'rocm-2.7.x'
-    String from_image = 'ci_test_nodes/rocm-2.7.x/ubuntu-16.04:latest'
+    String hcc_ver = 'rocm-2.8.x'
+    String from_image = 'ci_test_nodes/rocm-2.8.x/ubuntu-16.04:latest'
     String inside_args = '--device=/dev/kfd --device=/dev/dri --group-add=video'
 
     // Checkout source code, dependencies and version files