Adding XGboost Python sdk

[johnugeorge]

Added Python sdk for XGboost and e2e test in GHA actions

[coveralls]

Pull Request Test Coverage Report for Build 2468571581

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.02%) to 37.01%

---

Files with Coverage Reduction	New Missed Lines	%
pkg/controller.v1/mpi/mpijob_controller.go	5	78.0%

Totals
Change from base Build 2468470980:	-0.02%
Covered Lines:	2312
Relevant Lines:	6247

---

💛 - Coveralls

[terrytangyuan]

Thanks!

/lgtm

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: johnugeorge, terrytangyuan

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [johnugeorge,terrytangyuan]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment