Implement simple caching option

[shosca]

Mostly from sqlalchemy dogpile caching recipe with some tweaks

[coveralls]

Pull Request Test Coverage Report for Build 1087

• 44 of 44 (100.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build #904:	0.0%
Covered Lines:	3572
Relevant Lines:	3572

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💛 - Coveralls