Modernize repo. (kubernetes#179)

- Enable Mergify

- Run CircleCI to check all links

- Enable CODEOWNERS

Author: geeknoid

.circleci/config.yml

@@ -0,0 +1,20 @@
+version: 2
+jobs:
+  lint:
+    docker:
+      - image: gcr.io/istio-testing/circleci:2019-04-22
+    working_directory: /go/src/istio.io/community
+    steps:
+      - checkout
+      - run:
+          name: Installing linter
+          command: gem install awesome_bot
+      - run:
+          name: Linting
+          command: awesome_bot --skip-save-results --allow_ssl --allow-timeout --allow-dupe --allow-redirect --white-list *.md
+
+workflows:
+  version: 2
+  all:
+    jobs:
+      - lint

.mergify.yml

@@ -0,0 +1,13 @@
+pull_request_rules:
+  - name: Automatic merge on CI success and review
+    conditions:
+      - "status-success=ci/circleci: lint"
+      - status-success=cla/google
+      - "#approved-reviews-by>=1"
+      - label!=do-not-merge
+      - label!=do-not-merge/work-in-progress
+      - label!=do-not-merge/hold
+    actions:
+      merge:
+        method: squash
+        strict: false

CODEOWNERS

@@ -0,0 +1 @@
+* @geeknoid @linsun