Allows action to perform different operations based on inputs

[lstocchi]

This is related to #28

Now users can use the action to perform a different set of operations.

• If only the version is set the action will only download the oc executable requested and add it to the PATH so the following steps can have access to this

    steps:
    - name: OpenShift Action
      uses: redhat-developer/openshift-action
      with:
        version: '3.11.90'
    - name: scripttest
      run: |
        oc login --token=${{ secrets.API_TOKEN }} --server=${{ secrets.OPENSHIFT_SERVER_URL }}
        oc get pods | grep build

• If version, openshift_server_url and parameters are set, the action will download oc, set up the PATH and login to the cluster

    steps:
    - name: OpenShift Action
      uses: redhat-developer/openshift-action
      with:
        version: '3.11.90'
        openshift_server_url: ${{ secrets.OPENSHIFT_SERVER_URL }}
        parameters: '{"apitoken": "${{ secrets.API_TOKEN }}", "acceptUntrustedCerts": "true"}'
    - name: scripttest
      run:  oc get pods | grep build

• if version, openshift_server_url, parameters and commands are set the action will work as before