configure more github properties via asf.yaml (#58)

Author: dgrove-oss

.asf.yaml

@@ -31,3 +31,25 @@ github:
     - functions
     - openwhisk-runtime
     - ruby
+  protected_branches:
+    master:
+      required_status_checks:
+        strict: false
+        contexts:
+          - "Travis CI - Pull Request"
+      required_pull_request_reviews:
+        required_appoving_review_count: 1
+      required_signatures: false
+  enabled_merge_buttons:
+    merge: false
+    squash: true
+    rebase: true
+  features:
+    issues: true
+
+notifications:
+  commits: commits@openwhisk.apache.org
+  issues_status: issues@openwhisk.apache.org
+  issues_comment: issues@openwhisk.apache.org
+  pullrequests_status: issues@openwhisk.apache.org
+  pullrequests_comment: issues@openwhisk.apache.org