Small fixup.

Dockerfile

@@ -259,7 +259,7 @@ RUN apt-get update && \
     wget https://raw.githubusercontent.com/docker/compose/1.29.2/contrib/completion/bash/docker-compose -qO /etc/bash_completion.d/docker-compose && \
     wget https://raw.githubusercontent.com/ansible-community/molecule/1.25.1/asset/bash_completion/molecule.bash-completion.sh -qO /etc/bash_completion.d/molecule && \
     wget https://github.com/mrolli/packer-bash-completion/raw/master/packer -qO /etc/bash_completion.d/packer && \
-    mkdir /usr/local/share/ca-certificates && \
+    mkdir -p /usr/local/share/ca-certificates && \
     wget https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem  -qO - | \
         awk '/-----BEGIN[A-Z0-9 ]*CERTIFICATE-----/ {n++} n > 0 {print > ("/usr/local/share/ca-certificates/rds-" (1+n) ".crt")}' && \
     update-ca-certificates && \