install kubeadm

.travis.yml

@@ -11,10 +11,12 @@ addons:
   apt:
     packages:
       - docker-ce
-      - kubeadm
 
 before_install:
   - make dep
+  - curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
+  - echo "deb http://apt.kubernetes.io/ kubernetes-xenial main" | tee /etc/apt/sources.list.d/kubernetes.list
+  - apt-get update -qq && apt-get install -qy kubeadm
   - kubeadm init
 
 script: