github push hook for visualops.io

Signed-off-by: Wang Xu <xu@mc2.io>
implement visualops.io batch update API

- update all affected app as listed
- do not send req if branch do not listed
- pass Tests

Signed-off-by: Wang Xu <xu@mc2.io>
Test cases for visualops.io service

- test for app more than 2
- test for push to branch other than master (but listed)
- test for push to branch not list

Signed-off-by: Wang Xu <xu@mc2.io>
Doc for VisualOps service

Signed-off-by: Wang Xu <xu@mc2.io>
Use Service::HttpPost as parent
specify ssl port
Use general receive_event instead of receive_push

Signed-off-by: Wang Xu <xu@mc2.io>
use github deliver method and keep payload unchanged in body

Signed-off-by: Wang Xu <xu@mc2.io>
clean up code
remove unused definition in test

Signed-off-by: Wang Xu <xu@mc2.io>
Merge pull request #863 from MadeiraCloud/rebase

Add VisualOps.io to GitHub Service