feat: configurable @url@ timeout

mentioned in commit d6a29ea9

mentioned in merge request to-be-continuous/samples/golang-cnb-helm-on-kubernetes!78 (merged)

mentioned in merge request to-be-continuous/samples/golang-cnb-on-kubernetes!78

mentioned in merge request to-be-continuous/samples/golang-on-cloudfoundry!83 (merged)

mentioned in merge request to-be-continuous/samples/angular-on-s3!238

mentioned in merge request to-be-continuous/samples/golang-docker-on-aws!130 (merged)

mentioned in merge request to-be-continuous/samples/golang-cnb-on-kubernetes!80

mentioned in merge request to-be-continuous/samples/angular-on-s3!241 (merged)