updates integration tests to default to use cflinuxfs3
updates integration tests to default to use cflinuxfs3

[#161129755]

Co-authored-by: Daniel Thornton <5874b3971aa460e96f75d4dbef8f6aadb66f1697@pivotal.io>

cloudfoundry/go-buildpack,cloudfoundry/go-buildpack,cloudfoundry/go-buildpack