v1.2.0

• Upgrade to Kubernetes-1.15.3
• Upgrade to Go 1.13.0
• Added support for StatefulSets search
• Added support for -A as the shortcut of --all-namespaces
• Added support for install via kubectl krew install grep
• Fixed --help not work for the root command
• Support for command aliases:
  • daemonsets, daemonset, ds
  • deployments, deployment, deploy
  • hpas, hpa
  • nodes, node, no
  • pods, pod, po
  • statefulsets, stateful, sts