Upgrade pinot client version

[neil-xie]

What changed?
Upgrade pinot-go-client version to v0.2.0, it is the latest release version that supports pinot version 0.12.0 which is the version used internally

Why?

How did you test it?

Potential risks

Release notes

Documentation Changes

[coveralls]

Pull Request Test Coverage Report for Build 018daedd-c4d7-4e21-b456-76c002abd778

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 95 unchanged lines in 17 files lost coverage.
• Overall coverage decreased (-0.03%) to 62.721%

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Files with Coverage Reduction	New Missed Lines	%
client/history/client.go	2	38.1%
common/persistence/sql/sqlplugin/postgres/db.go	2	85.0%
common/persistence/sql/sqlplugin/postgres/task.go	2	73.4%
common/task/fifo_task_scheduler.go	2	85.57%
common/task/weighted_round_robin_task_scheduler.go	2	88.56%
service/history/execution/mutable_state_util.go	2	37.63%
service/history/handler.go	2	49.97%
service/matching/taskListManager.go	2	80.46%
service/matching/taskReader.go	2	84.88%
service/frontend/api/handler.go	4	62.11%

Totals
Change from base Build 018dae9f-1cbd-4682-94eb-c8ea3a325702:	-0.03%
Covered Lines:	92590
Relevant Lines:	147622

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💛 - Coveralls