As per https://bugs.debian.org/1029646, Cloudkitty often fails to build
as it fails its unit tests during the package build. This error happens
randomly. Sometimes it fails, sometimes it does not fail, but it's
clearly a false positive, because we don't really want the test to fail
in such case.
This patch makes it a lot less likely (10 times less) to happen by
increasing the tolerance.
Change-Id: If217a639f9af1e2693e6a132e46033df6bf96415