cli: remove dangling images before deploy

* Avoids having dangling docker images on the Kubernetes nodes
  because the Kubernetes Python library fails to list nodes (required
  by REANA-Commons and REANA-Server scheduler to determine if more
  workflows can be submitted) because of a validation error of data
  coming from the Kubernetes API. More information [here](kubernetes-client/python#895 (comment)).

* Tags the kindest/node image to latest because after installation
  it has `none` tag, which makes it count as a dangling image.

reana/cli.py

@@ -1783,6 +1783,7 @@ def job_mounts_to_config(job_mounts):
         namespace=namespace, values=yaml.dump(values_dict),
     )
     deploy_cmds = [
+        "docker images -f 'dangling=true' -q | xargs docker rmi -f",
         "helm dep update helm/reana",
         helm_install,
         "kubectl config set-context --current --namespace={}".format(namespace),
@@ -2200,6 +2201,8 @@ def add_volume_mounts(node):
         cluster_create,
         "reana-dev docker-pull -c reana",
         "reana-dev kind-load-docker-image -c reana",
+        "docker tag $(docker images -f 'dangling=true' 'kindest/node' -q) kindest/node:latest",
+        # avoid having kindest/node as a dangling image (no tag)
     ]:
         run_command(cmd, "reana")