Initial checkin: simple Keep server handling block reads only. (refs #2291)
Adding unit tests for GetBlock. (refs #2291)
Added unit tests TestGetBlockOneKeepOK and TestGetBlockFail (refs #2291)
Unit test TestGetBlockCorrupt. (refs #2291)
Incorporating comments from code review (refs #2438, refs #2291)
Improve readability of unit tests. (refs #2291)

Pass *testing.T object into setup/store functions to reduce
error-checking overhead.
Incorporating code review comments (refs #2291, refs #2438)
Merge branch '2291-new-keepd-read-blocks' (fixes #2291)