Build: update Node to version 8 LTS (carbon)

.npmrc

@@ -1,2 +1,2 @@
 save-exact = true
-
+package-lock = false

.nvmrc

@@ -1 +1 @@
-v6.11.5
+v8.9.1

Dockerfile

@@ -1,4 +1,4 @@
-FROM       node:6.11.5
+FROM       node:8.9.1
 MAINTAINER Automattic
 
 WORKDIR    /calypso
@@ -25,12 +25,9 @@ RUN        bash /tmp/env-config.sh
 # and should only change as often as the dependencies
 # change. This layer should allow for final build times
 # to be limited only by the Calypso build speed.
-#
-# Sometimes "npm install" fails the first time when the
-# cache is empty, so we retry once if it failed
 COPY       ./package.json ./npm-shrinkwrap.json /calypso/
 RUN        true \
-           && npm install --production || npm install --production \
+           && npm install --production \
            && rm -rf /root/.npm \
            && true
 

circle.yml

@@ -1,6 +1,6 @@
 machine:
   node:
-    version: 6.11.5
+    version: 8.9.1
 test:
   pre:
     - ? |