missing plugins directory

Version: v0.7.1

Overview

When this image is added as an init container for Velero (as documented here), the container's entrypoint fails with the following:

cp: can't stat '/plugins/*': Not a directory

Suspected cause

Running the image locally and overriding the entrypoint, to inspect the root directory shows that /plugins is a file rather than a directory.

This PR appears to have removed the line which created the /plugins directory, which means the corresponding COPY command is now creating a new file at /plugins rather than at /plugins/*.

Requested resolution

Reintroducing RUN mkdir /plugins line in the Dockerfile should resolve the behavior.