Bump lerna from 2.0.0 to 2.9.0

Bumps [lerna](https://github.com/lerna/lerna) from 2.0.0 to 2.9.0.
- [Release notes](https://github.com/lerna/lerna/releases?after=v3.0.0-alpha.0)
- [Changelog](https://github.com/lerna/lerna/blob/master/CHANGELOG.md)
- [Commits](lerna/lerna@v2.0.0...v2.9.0)

package.json

@@ -59,7 +59,7 @@
     "eslint-plugin-node": "^5.1.1",
     "eslint-plugin-promise": "^3.6.0",
     "eslint-plugin-standard": "^3.0.1",
-    "lerna": "^2.0.0",
+    "lerna": "^2.9.0",
     "mocha": "^4.0.1",
     "mocha-lcov-reporter": "^1.3.0",
     "nyc": "^11.3.0",