Add JobStorage

[patrick-ogrady]

Related Issue: coinbase/mesh-cli#112

This PR adds JobStorage and includes a collection of small nits required to make automated construction API testing work.

Changes

• Fix tests from Make Coordinator Fully Transactional #117
• refactor construction package into job, worker, and coordinator
• update broadcast storage with new interface
  • make BroadcastStorageHandler transactional
  • allow for CounterStorage to be transactional
• add job storage
  • expose # completed for a job type
• add coordinator handler for stats (matching pkg/constructor)
• remove wait from find account (can use address requirement to ensure always retry on same account during a funds request) -> just need to keep in own scenario after an address has been created
• support random_amount
• when transaction confirmed, parse balance changes and print
• force create new address with probability (otherwise will never create more addresses after first 2)

[coveralls]

Pull Request Test Coverage Report for Build 5613

• 175 of 209 (83.73%) changed or added relevant lines in 2 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.4%) to 78.495%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
constructor/worker/worker.go	76	91	83.52%
constructor/coordinator/coordinator.go	99	118	83.9%

Files with Coverage Reduction	New Missed Lines	%
constructor/coordinator/coordinator.go	2	69.59%

Totals
Change from base Build 5549:	0.4%
Covered Lines:	3358
Relevant Lines:	4278

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💛 - Coveralls

[cindyxkuang]

🚀

[heimdall-asguard]

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[heimdall-asguard]

Review Error for cindyxkuang @ 2020-09-01 00:09:19 UTC
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[cindyxkuang]

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