formatted minikube completion and used helper function

clean_files.txt

@@ -71,6 +71,7 @@ completion/available/jungle.completion.bash
 completion/available/knife.completion.bash
 completion/available/kontena.completion.bash
 completion/available/kubectl.completion.bash
+completion/available/minikube.completion.bash
 completion/available/packer.completion.bash
 completion/available/pip.completion.bash
 completion/available/pip3.completion.bash

completion/available/minikube.completion.bash

@@ -1,8 +1,6 @@
-#!/usr/bin/env bash
-
+# shellcheck shell=bash
 # minikube (Local Kubernetes) completion
 
-if command -v minikube &>/dev/null
-then
-  eval "$(minikube completion bash)"
+if _command_exists minikube; then
+	eval "$(minikube completion bash)"
 fi