Allow failures for coreos/weave

Unless https://github.com/kubernetes-incubator/kargo/issues/613
fixed.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

.travis.yml

@@ -106,6 +106,9 @@ env:
       CLUSTER_MODE=separate
       BOOTSTRAP_OS=coreos
 
+matrix:
+  allow_failures:
+    - env: KUBE_NETWORK_PLUGIN=weave CLOUD_IMAGE=coreos-stable CLOUD_REGION=europe-west1-b CLUSTER_MODE=default BOOTSTRAP_OS=coreos
 
 before_install:
   # Install Ansible.