osdmaptool: s/simple.t/missing-argument.t/

Signed-off-by: Loic Dachary <loic@dachary.org>
osdmaptool: test --import/export-crush

Signed-off-by: Loic Dachary <loic@dachary.org>
osdmaptool: tests for --test-map-pgs

Signed-off-by: Loic Dachary <loic@dachary.org>
Merge pull request #1196 from dachary/wip-osdmaptool

osdmaptool: additional tests