Clean up emulator check in Cosmos Test

[mdrichardson]

Description

Cosmos tests would throw errors in prep and cleanup scripts if both:

1. Cosmos Emulator installed at appropriate path
2. Cosmos Emulator was not running

Specific Changes

The Emulator check now only tries a GET request at the Emulator endpoint. If there is no response, it skips the prep and cleanup steps that would require emulator.

[coveralls]

Pull Request Test Coverage Report for Build 148355

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 9 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.07%) to 81.452%

---

Files with Coverage Reduction	New Missed Lines	%
libraries/botframework-streaming/src/webSocket/webSocketTransport.ts	2	80.65%
libraries/botframework-streaming/src/webSocket/webSocketServer.ts	7	66.67%

Totals
Change from base Build 147758:	-0.07%
Covered Lines:	13344
Relevant Lines:	15628

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💛 - Coveralls

[stevengum]

Do we need to perform a cleanup before we do the constructor tests?

https://github.com/microsoft/botbuilder-js/pull/2547/files#diff-e509e24b560c2c2464b96c7c9b2e119bR112

[mdrichardson]

@stevengum I wouldn't say that it's strictly necessary. Because cleanup erases all DBs and it isn't called until after in the "Base Storage Tests" section, there's a small chance that an existing DB could interfere with those tests.

[stevengum]

Blocking as @mdrichardson are iterating on this right now.