adds pull approve support

Author: casualjim

.pullapprove.yml

@@ -0,0 +1,13 @@
+approve_by_comment: true
+approve_regex: '^(:shipit:|:\+1:|\+1|LGTM|lgtm|Approved)'
+reject_regex: ^[Rr]ejected
+reset_on_push: false
+reviewers:
+  members:
+  - casualjim
+  - chancez
+  - frapposelli
+  - vburenin
+  - pytlesk4
+  name: pullapprove
+  required: 1