types: composite keys initial utils

[boz]

Initial work on handling composite keys decently.

refs #77

[coveralls]

Pull Request Test Coverage Report for Build 356

• 395 of 515 (76.7%) changed or added relevant lines in 22 files are covered.
• 7 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.6%) to 65.513%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
app/deployment/app.go	15	16	93.75%
app/fulfillment/app.go	9	10	90.0%
app/order/app.go	12	13	92.31%
cmd/akash/deployment.go	0	2	0.0%
cmd/akash/marketplace.go	0	2	0.0%
app/provider/app.go	1	4	25.0%
app/lease/app.go	19	31	61.29%
types/id.go	42	54	77.78%
keys/parse.go	51	67	76.12%
state/fulfillment.go	31	48	64.58%

Files with Coverage Reduction	New Missed Lines	%
cmd/akash/provider.go	1	44.68%
state/adapter.go	2	74.07%
app/deployment/app.go	4	51.14%

Totals
Change from base Build 353:	0.6%
Covered Lines:	3767
Relevant Lines:	5750

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💛 - Coveralls