Enabled to operate the version of kubeval

[wadason]

Hi. I want to use the new version of kubeval, so I made it possible to change the version of kubeval with an argument like other tools.

I have confirmed that the github actions I use in my project behave as intended.

here is my workflow.

- name: Run Kubernetes tools
      uses: wadason/kube-tools@add-kubeval-to-entrypoint
      with:
        kubectl: 1.18.2
        kustomize: 3.8.5
        kubeval: v0.16.1
        command: |
          echo "Run kubeval"
          kubeval --version

and here is output.

[stefanprodan]

LGTM

Thanks @wadason