Fix intermittent unit test failure
Fix intermittent unit test failure

test_check_delete_headers_removes_delete_after was
failing intermittently due to rounding of float time
values.

Change-Id: Ia126ad6988f387bbd2d1f5ddff0a56d457a1fc9b
Closes-Bug: #1743804

openstack/swift,smerritt/swift,smerritt/swift,matthewoliver/swift,matthewoliver/swift,tipabu/swift,swiftstack/swift,matthewoliver/swift,openstack/swift,tipabu/swift,smerritt/swift,smerritt/swift,swiftstack/swift,matthewoliver/swift,swiftstack/swift,tipabu/swift,openstack/swift,openstack/swift,tipabu/swift