spark3.0 support is not OK

[kingice]

On support spark3.0 branch,The MVN building get an error like :
[ERROR] Failed to execute goal on project sample_xgboost_apps: Could not resolve dependencies for project ai.rapids:sample_xgboost_apps:jar:0.2.2-SNAPSHOT: Failed to collect dependencies at ai.rapids:xgboost4j_3.0:jar:1.0.0-SNAPSHOT: Failed to read artifact descriptor for ai.rapids:xgboost4j_3.0:jar:1.0.0-SNAPSHOT: Could not transfer artifact ai.rapids:xgboost4j_3.0:pom:1.0.0-SNAPSHOT from/to spark.sw.nvidia.com (https://gpuwa.nvidia.com/artifactory/sw-spark-maven): gpuwa.nvidia.com: Unknown host gpuwa.nvidia.com -> [Help 1]

[wjxiz1992]

Hi, please try our new repo: https://github.com/NVIDIA/spark-xgboost-examples.

[kingice]

Hi, please try our new repo: https://github.com/NVIDIA/spark-xgboost-examples.

Thanks a lot！