🔧 Utiliser Yarn sur Heroku, supprimer npm

.gitignore

@@ -3,6 +3,5 @@
 node_modules/
 dist/
 .DS_Store
-yarn.lock
 package-lock.json
 yarn-error.log

package.json

@@ -28,7 +28,6 @@
 		"mocha": "^5.0.0",
 		"mocha-webpack": "^1.0.1",
 		"nearley": "^2.9.2",
-		"npm": "^5.3.0",
 		"ramda": "^0.25.0",
 		"rc-progress": "^2.2.5",
 		"react": "^16.2.0",
@@ -103,12 +102,11 @@
 	"scripts": {
 		"start": "node source/server.js",
 		"compile": "NODE_ENV='production' webpack --config source/webpack.config.js",
-		"surge": "npm run compile && surge --domain scientific-wish.surge.sh -p ./ && rm -rf dist/",
 		"test": "mocha-webpack --webpack-config source/webpack.test.config.js --require source-map-support/register --require test/helpers/browser.js \"test/**/*.test.js\"",
 		"test-watch": "mocha-webpack --webpack-config source/webpack.test.config.js --require source-map-support/register --require test/helpers/browser.js \"test/**/*.test.js\" --watch",
 		"test-meca": "mocha-webpack --webpack-config source/webpack.test.config.js --require source-map-support/register --require test/helpers/browser.js test/mecanisms.test.js --watch",
 		"test-rules": "mocha-webpack --webpack-config source/webpack.test.config.js --require source-map-support/register --require test/helpers/browser.js test/real-rules.test.js --watch",
-		"heroku-postbuild": "npm install --dev && webpack --config source/webpack.config.js --progress",
+		"heroku-postbuild": "yarn install --production=false && webpack --config source/webpack.config.js --progress",
 		"test-inversions": "mocha-webpack --webpack-config source/webpack.test.config.js --require source-map-support/register --require test/helpers/browser.js \"test/inversion.test.js\" --watch"
 	}
 }