run lint before test

Author: bahmutov

package.json

@@ -29,6 +29,7 @@
     "lint": "prettier-eslint --write '*.js'",
     "secure": "nsp check",
     "size": "t=\"$(npm pack .)\"; wc -c \"${t}\"; tar tvf \"${t}\"; rm \"${t}\";",
+    "pretest": "npm run lint",
     "test": "mocha",
     "test-debug": "node --inspect --debug-brk ./node_modules/.bin/_mocha",
     "test-watch": "chokidar '*.js' 'test/*.js' -c 'npm test'",