chore(package): update lockfile

https://npm.im/greenkeeper-lockfile

Author: greenkeeperio-bot

yarn.lock

@@ -1955,9 +1955,9 @@ [email protected]:
   optionalDependencies:
     esdoc "^0.5.2"
 
-[email protected].3:
-  version "3.6.3"
-  resolved "https://registry.yarnpkg.com/danger/-/danger-3.6.3.tgz#007e04c151681ec951061322e73decaddb0fe6bf"
+[email protected].4:
+  version "3.6.4"
+  resolved "https://registry.yarnpkg.com/danger/-/danger-3.6.4.tgz#c5f02b5154bcd7cee111bb910fe6c9d7c811333f"
   dependencies:
     "@octokit/rest" "^15.2.6"
     babel-polyfill "^6.23.0"