Update ci.yml

Signed-off-by: Tamal Saha <tamal@appscode.com>

Author: tamalsaha

.github/workflows/ci.yml

@@ -45,7 +45,7 @@ jobs:
     needs: build
     strategy:
       matrix:
-        k8s: [v1.12.10, v1.13.12, v1.14.10, v1.15.11, v1.16.9, v1.17.5, v1.18.2]
+        k8s: [v1.12.10, v1.13.12, v1.14.10, v1.15.11, v1.16.9, v1.17.5, v1.18.4]
     steps:
       - name: Check out code into the Go module directory
         uses: actions/checkout@v1