In cases like the segment reaper script connecting to the metainfodb,
we don't want a db migration to happen automatically when we call
metainfo.NewStore. This adds MigrateToLatest method for postgreskv
and cockroackv, and calls MigrateToLatest in places where NewStore used
to create tables.
Change-Id: I682d0f26d609af0601dfdb32a24866cdf5d32a7e
Currently storage tests were tied to the default lookup limit.
By increasing the limits, the tests will take longer and sometimes
cause a large number of goroutines to be started.
This change adds configurable lookup limit to all storage backends.
Also remove boltdb.NewShared, since it's not used any more.
Change-Id: I1a052f149da471246fac5745da133c3cfc27582e