DevEx: use yarn instead of npm for installing dependencies

.gitattributes

@@ -1 +1,2 @@
 npm-shrinkwrap.json binary
+yarn.lock binary

Dockerfile

@@ -26,9 +26,9 @@ 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.
-COPY       ./package.json ./npm-shrinkwrap.json /calypso/
+COPY       ./package.json ./yarn.lock /calypso/
 RUN        true \
-           && npm install --production \
+           && yarn install --production \
            && rm -rf /root/.npm \
            && true
 
@@ -56,7 +56,7 @@ RUN        touch node_modules
 ARG        commit_sha="(unknown)"
 ENV        COMMIT_SHA $commit_sha
 
-RUN        CALYPSO_ENV=production npm run build
+RUN        CALYPSO_ENV=production yarn run build
 
 USER       nobody
 CMD        NODE_ENV=production node build/bundle.js

circle.yml

@@ -1,40 +1,44 @@
 machine:
   node:
     version: 8.9.4
+dependencies:
+  override:
+    - yarn
 test:
   pre:
     - ? |
           # make the build-server and i18n string data in parallel
-          if [[ "$CIRCLE_NODE_INDEX" == 0 ]]; then NODE_ENV=test npm run build-server; fi
+          if [[ "$CIRCLE_NODE_INDEX" == 0 ]]; then NODE_ENV=test yarn run build-server; fi
           if ( [[ "$CIRCLE_NODE_INDEX" == 1 ]] || [[ "$CIRCLE_NODE_TOTAL" == 1 ]] ) && [[ "$CIRCLE_BRANCH" == "master" ]]; then
-            npm run translate; mkdir -p $CIRCLE_ARTIFACTS/translate; mv calypso-strings.pot $CIRCLE_ARTIFACTS/translate
+            yarn run translate; mkdir -p $CIRCLE_ARTIFACTS/translate; mv calypso-strings.pot $CIRCLE_ARTIFACTS/translate
           elif [[ "$CIRCLE_NODE_INDEX" == 1 ]] || [[ "$CIRCLE_NODE_TOTAL" == 1 ]]; then
             git clone https://github.com/Automattic/gp-localci-client.git
             bash gp-localci-client/generate-new-strings-pot.sh $CIRCLE_BRANCH $CIRCLE_SHA1 $CIRCLE_ARTIFACTS/translate
             rm -rf gp-localci-client
           fi
       : parallel: true
   override:
+    - yarn
     - bin/run-integration:
         parallel: true
         files:
           - bin/**/integration/*.js
           - client/**/integration/*.js
           - server/**/integration/*.js
-    - npm run lint:config-defaults
+    - yarn run lint:config-defaults
     - ./node_modules/.bin/eslint-eslines:
         parallel: true
         files:
           - client/**/*.js
           - client/**/*.jsx
           - server/**/*.js
           - server/**/*.jsx
-    - npm run test-client:ci:
+    - yarn run test-client:ci:
         parallel: true
         files:
           - client/**/test/*.js
           - client/**/test/*.jsx
-    - npm run test-server:ci:
+    - yarn run test-server:ci:
         parallel: true
         files:
           - server/**/test/*.js