Add support to configure webhook_timeout in gitlab.yaml

Created by: wesgurn

Our Gitlab instance needed the ability to increase the webhook_timeout used by HTTParty. It was hardcoded at 10 and I moved it to a gitlab.yaml file as a config variable

Webhook settings

webhook_timeout: 30 # default: 10 - Number of seconds to wait for HTTP response after sending webhook HTTP POST request

lib/tasks/travis.rake

-desc "Travis run tests"
-task travis: [
-  :spinach,
-  :spec
-]