Increase seach scope on syslog tests
Increase seach scope on syslog tests

**Problem**: Papertrail API establishes by default a [5 seconds limit]
(http://help.papertrailapp.com/kb/how-it-works/http-api/#api-rate-limits)
to perform event searches. In some cases, the search lasts for more than that
limit making syslog tests fail.

**Solution**: start using a `min_time` parameter in the papertrail test requests
so that we can search using a time period based on log timestampts
instead of using query time limits.

[#136341747]

Signed-off-by: Zhou Yu <7f3430145af357a9fd7cb1a2d072f9b26e6234cb@pivotal.io>
Signed-off-by: Diego Lemos <48d75b1e8d05d722a97d5c3ce49024e6a466bebe@pivotal.io>

pivotal-cf/cf-rabbitmq-release,pivotal-cf/cf-rabbitmq-release,pivotal-cf/cf-rabbitmq-release,pivotal-cf/cf-rabbitmq-release