try different version

Signed-off-by: wenqi <Wenqi.Mou@emc.com>

.travis.yml

@@ -18,7 +18,7 @@ services:
 
 install:
 - curl -Lo kubectl https://storage.googleapis.com/kubernetes-release/release/$KUBERNETES_VERSION/bin/linux/amd64/kubectl && chmod +x kubectl && sudo mv kubectl /usr/local/bin/
-- curl -Lo minikube https://storage.googleapis.com/minikube/releases/v0.33.1/minikube-linux-amd64 && chmod +x minikube && sudo mv minikube /usr/local/bin/
+- curl -Lo minikube https://storage.googleapis.com/minikube/releases/v0.30.0/minikube-linux-amd64 && chmod +x minikube && sudo mv minikube /usr/local/bin/
 - curl -Lo dep https://github.com/golang/dep/releases/download/v0.5.0/dep-linux-amd64 && chmod +x dep && sudo mv dep /usr/local/bin/
 - curl -Lo operator-sdk https://github.com/operator-framework/operator-sdk/releases/download/v0.2.0/operator-sdk-v0.2.0-x86_64-linux-gnu && chmod +x operator-sdk && sudo mv operator-sdk /usr/local/bin/
 - curl -Lo helm.tar.gz https://storage.googleapis.com/kubernetes-helm/helm-v2.12.0-linux-amd64.tar.gz && tar xfz helm.tar.gz && sudo mv linux-amd64/{helm,tiller} /usr/local/bin/