Added integration tests for registry

Lint Python code for syntax errors and undefined names

Show more relevant information, when using none driver

Makefile improvements for the kvm2 driver

Move supported drivers per platform

refactoring and simplifying start command

docker://gcr.io/k8s-minikube/kvm-build-image:latest

Make sure that we don't link with libvirt 2.0.0+ by mistake.

Don't need to link the LXC library, as we are not using it.

We should respect the MINIKUBE_BUILD_IN_DOCKER param,
and also make the "docker inspect" output less verbose

And make the windows target repeatable, by leaving the
original output binary (copy instead of move) behind

Extract Advice strings for localization

Lint Python code for issues like  #4741 and  #4762.

Add linux packaging for the kvm2 driver binary

Upgrade crio to 1.15.0

Create package index files, for apt and yum

Undefined name 'test' in run_tests.py

This issue was hidden by the syntax error in #4741

$ __time flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics__
```
./hack/prow/run_tests.py:28:32: F821 undefined name 'test'
  classname = os.path.basename(test).split('.')[0]
                               ^
1     F821 undefined name 'test'
1
```

Update crictl to v1.15.0

Use print() function in both Python 2 and Python 3

Upgrade Podman to 1.4

But don't have any signing infrastructure yet

Need somewhere to store the private gpg keys.

Add documentation of the parallels vm-driver

Use tempfile for extract test

Revert "Refactor status command"

Reduce kubectl restart time from 10 seconds to 600ms