Ingress NGINX: Promote NGINX v0.3.1.

Author: Gacko

registry.k8s.io/images/k8s-staging-ingress-nginx/images.yaml

@@ -225,6 +225,7 @@
     "sha256:87dcd5ed0206161b86f3767ccdc592716617481e3eac89bfc46ec515419c0b94": ["v0.1.0"]
     "sha256:df33459aa3ef83c62d7fb1f1eafc872cf322fa342c0ec97a2533e844267d45b4": ["v0.2.0"]
     "sha256:73b4df804b128dc7aed9a769e17e9eaa70304895f26115c3d57e44e08ecc3685": ["v0.3.0"]
+    "sha256:95583e4278a30f52e2690432a6625c9b86a400c780a657bb0a6f170994a10eb4": ["v0.3.1"]
     "sha256:11ee0d0e3d063f1468f9a82958d57fa0718614fe10b676941f4dea0aef091faf": ["v1.0.0"]
     "sha256:43e04f78d7544010e2e86918faae1d15091995b7ef6e522f53cf3035ad814567": ["v1.1.0"]
     "sha256:c4b3f79fb88eab2ac03bde5c6b8340ffad941e0fce0eaa797e98481683b3b5aa": ["v1.2.0"]