Dont run changelog before version because it breaks when there were no changes

Author: rattrayalex

package.json

@@ -53,7 +53,7 @@
     "clean": "rimraf lib",
     "flow": "flow",
     "prepublish": "cross-env BABEL_ENV=production npm run build",
-    "preversion": "npm run test && npm run changelog",
+    "preversion": "npm run test",
     "test": "npm run lint && npm run flow && npm run build -- -m && npm run test-only",
     "test-only": "ava",
     "test-ci": "nyc npm run test-only",