integrity: implement integrity.Storage

[bigbes]

Closes TNTP-4191

[coveralls]

Pull Request Test Coverage Report for Build 20179339081

Details

• 315 of 622 (50.64%) changed or added relevant lines in 10 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+5.2%) to 25.392%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
crypto/rsapss.go	2	3	66.67%
namer/namer.go	118	120	98.33%
namer/results.go	32	34	94.12%
marshaller/marshaller.go	1	22	4.55%
integrity/generator.go	39	62	62.9%
integrity/validator.go	85	127	66.93%
integrity/builder.go	0	104	0.0%
integrity/storage.go	0	112	0.0%

Files with Coverage Reduction	New Missed Lines	%
driver/etcd/etcd.go	2	82.93%

Totals
Change from base Build 19701817310:	5.2%
Covered Lines:	907
Relevant Lines:	3572

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💛 - Coveralls