[fetcher] Optionally Force Retry

[patrick-ogrady]

This PR allows the caller to specify that all non-200 responses from a Rosetta implementation should be retried. This is particularly useful when accessing a Rosetta implementation through a load balancer where there may be periods of inconsistency (i.e. we get a network status from one implementation and query another that has not yet synced the most recent block).

Changes

• Add WithForceRetry option to fetcher
• Add test

Future Work

• Add force_retry to rosetta-cli

[coveralls]

Pull Request Test Coverage Report for Build 13627

• 5 of 5 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.008%) to 78.062%

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Totals
Change from base Build 13595:	0.008%
Covered Lines:	8095
Relevant Lines:	10370

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💛 - Coveralls

[yfl92]

LGTM

[heimdall-asguard]

Review Error for yflinn @ 2020-12-11 19:12:41 UTC
User failed mfa authentication, see go/mfa-help