Remove LightGBMBooster's mergeModels function

[ywskycn]

Discussed in #315, the merge function doesn't need anymore. Would better to remove it.

[imatiach-msft]

LGTM, thank you!

[mmlspark-bot]

Canceled! — The build has canceled. (dc68095b)

[mmlspark-bot]

Canceled! — The build has canceled. (dc68095b)

[mmlspark-bot]

Canceled! — The build has canceled. (dc68095b)

[ywskycn]

@imatiach-msft @mhamilton723 know how to make the build-pr happy? :)

[imatiach-msft]

@ywskycn yes, sorry, there was a major refactor that @mhamilton723 recently did to use Azure Databricks cluster for our tests instead of HDInsight and now it looks like the e2e builds are getting stuck, he is looking into it. The PR will be checked in as soon as the build issue is resolved, sorry for the inconvenience.

[mhamilton723]

Sorry @ywskycn this is not your issue and I will check this in as soon as I iron out the build kinks, hopefully by tomorrow. If this is a blocker please let us know

[mhamilton723]

@ywskycn could you quickly rebase your changes on latest master so we can push it through the new build? Thanks!

[mmlspark-bot]

Pass! — The build has succeeded. (e0d7a7fe)

MMLSpark 0.12.dev20+2.ge0d7a7f

This is a build for Github PR #316, changes:

• [e0d7a7f] 严伟 Merge branch 'master' into RemoveMerge
• [dc68095] 严伟 Remove LightGBMBooster's mergeModels function

---

• Source: ywskycn/mmlspark,
  RemoveMerge at revision e0d7a7f
  (by 严伟 wei.yan@antfin.com).

• Build: MMLSpark, 1063333
  (built by elbarzil-vm on elbarzil-vm, 2018-06-19 00:39)

• Info:
  0.12.dev20+2.ge0d7a7f: ywskycn/mmlspark/RemoveMerge@e0d7a7fe; MMLSpark#1063333

• Queued by:
  Mark Hamilton for Mark Hamilton

• Maven package uploaded, use --packages com.microsoft.ml.spark:mmlspark_2.11:0.12.dev20+2.ge0d7a7f and --repositories https://mmlspark.azureedge.net/maven.

• PIP package uploaded.

• R package uploaded.

• HDInsight: Copy the link to this Script Action to setup this build on a cluster.

• ARM Template: Use this ARM Template to setup a cluster with a gpu (in the portal).

  • HDI Sub-Template: Use the HDI sub-template for just the hdi deployment (in the portal).

  • GPU VM Sub-Template: Use the GPU sub-template for just the gpu vm deployment (in the portal).

  • Convenient Deployment Script: Download this bash script or this powershell script, create a paramers file based on this template, and run as

    ./deploy-arm.sh ... -p <your-parameters>
    

• Documentation uploaded.