Add cleanup code to vagrant AWS cluster test task.
Add cleanup code to vagrant AWS cluster test task.

  + Should use ensure in the future to guarantee VM deletion.

[#100138120]

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