Add some extra local kubernetes environments to ci/infra

[inercia]

Our current end-to-end tests are based on the clusters created by the cluster providers at ci/infra. In order to test the integration of the Operator in some of these environments, we should create some extra providers for:

• KIND
• minikube
• (maybe) k3s (note well that we already support k3d).

Technical hints

For minikube, take a look at https://github.com/lilic/travis-minikube

Acceptance criteria

• [x] There is a new cluster provider for LXC that can be used for running end-to-end tests for kops/kubespray.
• [x] There is a new cluster provider for KIND that can be used for running end-to-end tests
• [ ] There is a new cluster provider for minikube that can be used for running end-to-end tests

[inercia]

On hold until we know the PRs that are accepted...

[khussey]

@concaf looks like just the cluster provider for minikube is outstanding now.