chore(package): update lockfile

https://npm.im/greenkeeper-lockfile

Author: greenkeeperio-bot

yarn.lock

@@ -1745,9 +1745,9 @@ flat-cache@^1.2.1:
     graceful-fs "^4.1.2"
     write "^0.2.1"
 
-flow-bin@0.49.1:
-  version "0.49.1"
-  resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.49.1.tgz#c9e456b3173a7535a4ffaf28956352c63bb8e3e9"
+flow-bin@0.51.0:
+  version "0.51.0"
+  resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.51.0.tgz#97a3c511a17caa25d8fad58fc17aaabcb86319fe"
 
 follow-redirects@0.0.7:
   version "0.0.7"