Retention policy creation not enforcing minimum retention duration

[corylanou]

You can currently create a RP with a duration of 1s. We used to have a minimum but I can't remember what it is. It should be more than 1s though I would think.

There is a test in cmd/influxd/run/server_test.go, testname: TestServer_RetentionPolicyCommands, table test: Ensure retention policy with unacceptable retention cannot be created that is currently skipped that is able to replicate the issue.

[otoolep]

@corylanou - this minimum used to be 1 hour.

[beckettsean]

@corylanou confirming the minimum RP duration was 1 hour: #2760.

Is max still correct? #2762

[otoolep]

#3027

[otoolep]

All fixed for 0.9.1