Add scripts folder to shellcheck

Signed-off-by: Jean-Pierre Huynh <jean-pierre.huynh@ounet.fr>

scripts/test/unit-with-coverage

@@ -3,14 +3,14 @@ set -eu -o pipefail
 
 # install test dependencies once before running tests for each package. This
 # reduces the runtime from 200s down to 23s
-go test -i $@
+go test -i "$@"
 
-for pkg in $@; do
+for pkg in "$@"; do
     ./scripts/test/unit \
         -cover \
         -coverprofile=profile.out \
         -covermode=atomic \
-        ${pkg}
+        "${pkg}"
     
     if test -f profile.out; then
         cat profile.out >> coverage.txt