Change shell check name, as it's confusing

Change shell check name, as it's confusing

When you look at the build there is

opnfvdocs-verify-master (opnfvdocs project)
opnfv-docs-verify-master (releng project)

It's not clear on first glance which build does what.
change opnfvdocs-verify-{stream} to 'opnfvdocs-verify-shellcheck-{stream}'
change opnfvdocs-merge-{stream} to 'opnfvdocs-merge-shellcheck-{stream}'

Change-Id: I11927c9ac9b7ae6f9ae44660ea5008713a1b0a9f
Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>