chore: run eslint only once when testing on travis

Author: ZauberNerd

package.json

@@ -30,9 +30,9 @@
     "prebuild": "npm run test:unit",
     "build": "rimraf distribution/ && babel source/ --out-dir distribution/ --ignore **/*.spec.js",
     "prepublish": "npm run build",
-    "pretest:unit": "npm run lint && npm run flow",
+    "pretest:unit": "npm run flow",
     "test:unit": "ava",
-    "test": "npm run test:unit && tav"
+    "test": "npm run lint && npm run test:unit && tav"
   },
   "ava": {
     "files": [