Fix conformance v1.14, v1.13 (apache#635)

GOMODULE=ON causing problem in conformance tests v1.14 and v1.13,
disabled it for v1.14 and v1.13

Author: adisky

playbooks/cloud-provider-openstack-acceptance-test-e2e-conformance/run.yaml

@@ -112,6 +112,12 @@
           # Build all binaries
           export KUBE_FASTBUILD=true
           export KUBERNETES_CONFORMANCE_TEST=y
+          # Go modules not supported by kubernetes before v1.15
+          if [ '{{ k8s_version }}' == 'release-1.13' || '{{ k8s_version }}' == 'release-1.14' ]; then
+            unset GO111MODULE
+            unset GOSUMDB
+            unset GOPROXY
+          fi
 
           # TEMP - Dump Memory Every Second
           free -lmthw -c10000 >> $LOG_DIR/system_memory.log &