Update "cross-env" to the latest version, which includes a fix for c…

…ommands in Windows with undefined env variables

Fixes #16452
Closes #19084

The latest version of `cross-env` (`5.1.1`) includes a fix to #16452.
The fix is: kentcdodds/cross-env#149
Now the behaviour of commands like `cross-env node $UNDEFINED_VAR index.js` is expanding the variable
to the empty string, both in Windows and in UNIX.

To get the new version of `cross-env` working, I had to change all `cross-env` commands to `cross-env-shell`,
as this was a breaking change on `cross-env@5`.

To test: run `npm start` on a Windows `cmd.exe` shell, check that it works.

cc/ @Viper007Bond @withinboredom

package.json

@@ -52,7 +52,7 @@
     "copy-webpack-plugin": "4.0.1",
     "create-react-class": "15.6.2",
     "creditcards": "2.1.2",
-    "cross-env": "4.0.0",
+    "cross-env": "5.1.1",
     "d3-array": "1.2.0",
     "d3-scale": "1.0.6",
     "d3-selection": "1.1.0",
@@ -166,7 +166,7 @@
     "npm": "5.5.1"
   },
   "scripts": {
-    "preanalyze-bundles": "cross-env WEBPACK_OUTPUT_JSON=1 CALYPSO_ENV=production npm run -s env -- node --max_old_space_size=8192 ./node_modules/.bin/webpack --config webpack.config.js --profile --json > stats.json",
+    "preanalyze-bundles": "cross-env-shell WEBPACK_OUTPUT_JSON=1 CALYPSO_ENV=production npm run -s env -- node --max_old_space_size=8192 ./node_modules/.bin/webpack --config webpack.config.js --profile --json > stats.json",
     "analyze-bundles": "webpack-bundle-analyzer stats.json public -h 0.0.0.0 -p 9898",
     "analyze-css": "node bin/analyze-css.js",
     "autoprefixer": "postcss -r --use autoprefixer",
@@ -199,10 +199,10 @@
     "clean:public": "npm run -s rm -- public .css .css.map .js .js.map && npm run -s rm -- public/sections .css .css.map && npm run -s rm -- public/sections-rtl .css .css.map",
     "codemod": "node bin/codemods/run",
     "predashboard": "npm run -s install-if-deps-outdated",
-    "dashboard": "cross-env DASHBOARD=1 webpack-dashboard -- npm start",
+    "dashboard": "cross-env-shell DASHBOARD=1 webpack-dashboard -- npm start",
     "distclean": "npm run -s clean && npm run -s rm -- node_modules",
     "docker": "docker run -it --name wp-calypso --rm -p 80:3000 -e NODE_ENV=wpcalypso -e CALYPSO_ENV=wpcalypso wp-calypso",
-    "env": "cross-env NODE_PATH=$NODE_PATH:server:client:.",
+    "env": "cross-env-shell NODE_PATH=$NODE_PATH:server:client:.",
     "eslint-branch": "node bin/eslint-branch.js",
     "install-if-deps-outdated": "node bin/install-if-deps-outdated.js",
     "install-if-no-packages": "node bin/install-if-no-packages.js",
@@ -218,21 +218,21 @@
     "postshrinkwrap": "node bin/trim-shrinkwrap.js && touch node_modules",
     "prestart": "npm run -s install-if-deps-outdated && node bin/welcome.js && ( check-node-version --package || exit 0 )",
     "start": "npm run -s build",
-    "poststart": "npm run -s env -- cross-env node $NODE_ARGS build/bundle.js",
+    "poststart": "npm run -s env -- cross-env-shell node $NODE_ARGS build/bundle.js",
     "reformat-files": "node bin/reformat-files.js",
     "pretest": "npm run -s install-if-deps-outdated",
     "test": "run-s -s test-client test-server",
     "pretest-client": "npm run -s pretest",
     "test-client": "jest -c=test/client/jest.config.json",
-    "test-client:ci": "cross-env TEST_REPORT_FILENAME=./test-results-client.xml jest -c=test/client/jest.config.ci.js -w=2",
+    "test-client:ci": "cross-env-shell TEST_REPORT_FILENAME=./test-results-client.xml jest -c=test/client/jest.config.ci.js -w=2",
     "test-client:watch": "npm run -s test-client -- --watch",
     "pretest-integration": "npm run -s pretest",
     "test-integration": "jest -c=test/integration/jest.config.json",
-    "test-integration:ci": "cross-env TEST_REPORT_FILENAME=./test-results-integration.xml jest -c=test/integration/jest.config.ci.js -w=2",
+    "test-integration:ci": "cross-env-shell TEST_REPORT_FILENAME=./test-results-integration.xml jest -c=test/integration/jest.config.ci.js -w=2",
     "test-integration:watch": "npm run -s test-integration -- --watch",
     "pretest-server": "npm run -s pretest",
     "test-server": "jest -c=test/server/jest.config.json",
-    "test-server:ci": "cross-env TEST_REPORT_FILENAME=./test-results-server.xml jest -c=test/server/jest.config.ci.js -w=2",
+    "test-server:ci": "cross-env-shell TEST_REPORT_FILENAME=./test-results-server.xml jest -c=test/server/jest.config.ci.js -w=2",
     "test-server:coverage": "npm run -s test-server -- --coverage",
     "test-server:watch": "npm run -s test-server -- --watch",
     "translate": "i18n-calypso --format pot --output-file ./calypso-strings.pot -e date \"**/*.js\" \"**/*.jsx\" \"!build/**\" \"!node_modules/**\" \"!public/**\" \"!client/extensions/**\"",