chore(package): update lockfile

https://npm.im/greenkeeper-lockfile

Author: greenkeeperio-bot

yarn.lock

@@ -1900,14 +1900,15 @@ levn@^0.3.0, levn@~0.3.0:
     prelude-ls "~1.1.2"
     type-check "~0.3.2"
 
-lint-staged@^5.0.0:
-  version "5.0.0"
-  resolved "https://registry.yarnpkg.com/lint-staged/-/lint-staged-5.0.0.tgz#f1c670e03e2fdf3f3d0eb81f72d3bcf658770e54"
+lint-staged@6.0.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/lint-staged/-/lint-staged-6.0.0.tgz#7ab7d345f2fe302ff196f1de6a005594ace03210"
   dependencies:
     app-root-path "^2.0.0"
     chalk "^2.1.0"
     commander "^2.11.0"
     cosmiconfig "^3.1.0"
+    debug "^3.1.0"
     dedent "^0.7.0"
     execa "^0.8.0"
     find-parent-dir "^0.3.0"