fix: add a tag, goleveldb, to test_cover.sh

contrib/test_cover.sh

@@ -6,7 +6,7 @@ PKGS=$(go list ./... | grep -v '/simapp')
 set -e
 echo "mode: atomic" > coverage.txt
 for pkg in ${PKGS[@]}; do
-    go test -v -timeout 30m -race -coverprofile=profile.out -covermode=atomic -tags='ledger test_ledger_mock' "$pkg"
+    go test -v -timeout 30m -race -coverprofile=profile.out -covermode=atomic -tags='ledger test_ledger_mock goleveldb' "$pkg"
     if [ -f profile.out ]; then
         tail -n +2 profile.out >> coverage.txt;
         rm profile.out