remove old READMEs/CHANGELOGs from gemspecs
remove old READMEs/CHANGELOGs from gemspecs

cloudfoundry-incubator/bosh-vsphere-cpi-release,nimbus-cloud/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,nimbus-cloud/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,nimbus-cloud/bosh-vsphere-cpi-release