Bump compilation VMs to c4.large
Bump compilation VMs to c4.large

cloudfoundry-attic/v1-dummy-broker-release,cloudfoundry-incubator/v1-dummy-broker-release,cloudfoundry-incubator/v1-dummy-broker-release,cloudfoundry-attic/v1-dummy-broker-release,cloudfoundry-incubator/v1-dummy-broker-release,cloudfoundry-incubator/v1-dummy-broker-release,cloudfoundry-attic/v1-dummy-broker-release,cloudfoundry-attic/v1-dummy-broker-release