Adding GHA for automatic image build and push

[johnugeorge]

Adds GHA workflow to build and push docker images

[coveralls]

Pull Request Test Coverage Report for Build 2500801045

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.04%) to 41.355%

---

Files with Coverage Reduction	New Missed Lines	%
pkg/controller.v1/mpi/mpijob_controller.go	2	77.8%

Totals
Change from base Build 2496976945:	-0.04%
Covered Lines:	2289
Relevant Lines:	5535

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💛 - Coveralls

[terrytangyuan]

Thanks!

/lgtm
/approve

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

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

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