Upgrade Terraform to v0.5.1 in lattice-pipeline image.
Upgrade Terraform to v0.5.1 in lattice-pipeline image.

  + Squash layers in lattice-pipeline image.

[Finishes #94818394]

Signed-off-by: Kristie-Lynne Koss <b6ebd6e8bc77ed89e2b529234243864da8b54e7b@pivotal.io>

SrinivasChilveri/lattice,svrc-pivotal/lattice,SrinivasChilveri/lattice,felipeg48/lattice,davidwadden/lattice-release,datachand/lattice,datachand/lattice,svrc-pivotal/lattice,cloudfoundry-incubator/ltc,svrc-pivotal/lattice,cloudfoundry-incubator/ltc,Klaudit/lattice,davidwadden/lattice,Klaudit/lattice,davidwadden/lattice-release,svrc-pivotal/lattice,davidwadden/lattice,Klaudit/lattice,SrinivasChilveri/lattice,datachand/lattice,datachand/lattice,SrinivasChilveri/lattice,felipeg48/lattice,Klaudit/lattice