update to Python3

Author: emmajingwang

openshift/client-build-config.yaml

@@ -64,7 +64,7 @@ objects:
           FROM image-registry.openshift-image-registry.svc:5000/55b94d-tools/node:1 AS builder
           LABEL maintainer="[email protected]"
           RUN apk add --no-cache --virtual .gyp \
-            python \
+            python3 \
             make \
             g++
       strategy: