Add crates.io Codecov badge (deactivated)
Add crates.io Codecov badge (deactivated)

Just added the required manifest entry required to add the Codecov badge
to the crates.io welcome page, but it will not show for now: it is commented
out. One can simple remove the leading '#' and it will activated.

Signed-off-by: Paul Mabileau <a3aedf8c87c1af3dfeae5f57ddf6d5ae82ad981f@hotmail.fr>

sunjay/turtle,sunjay/turtle,sunjay/turtle