helper function to run conftest policies against specific version

[garethahealy]

Add a helper function to:

• https://github.com/redhat-cop/bats-library/blob/master/src/conftest.bash

which filters out (i.e.: rm {file}) which don't match what version is requested

if k8s = 1.20
rm anything that is greater than kubernetes-1.20.rego

• https://github.com/swade1987/deprek8ion/tree/master/policies

if k8s = 4_2
rm anything that is greater than 4_2/
https://github.com/redhat-cop/rego-policies/tree/master/policy/ocp/deprecated