fix(deps): update dependency graphql-playground-middleware-express to v1.5.6

Author: renovate-bot

package.json

@@ -45,7 +45,7 @@
     "express": "^4.16.2",
     "graphql": "^0.12.0",
     "graphql-import": "^0.4.1",
-    "graphql-playground-middleware-express": "1.5.3",
+    "graphql-playground-middleware-express": "1.5.6",
     "graphql-playground-middleware-lambda": "1.4.0",
     "graphql-subscriptions": "^0.5.6",
     "graphql-tools": "^2.18.0",

yarn.lock

@@ -461,17 +461,17 @@ graphql-playground-html@1.5.0:
   version "1.5.0"
   resolved "https://registry.yarnpkg.com/graphql-playground-html/-/graphql-playground-html-1.5.0.tgz#bfe1a53e8e7df563bdbd20077e0ac6bf9aaf0f64"
 
-graphql-playground-html@1.5.2:
-  version "1.5.2"
-  resolved "https://registry.yarnpkg.com/graphql-playground-html/-/graphql-playground-html-1.5.2.tgz#ccd97ac1960cfb1872b314bafb1957e7a6df7984"
+graphql-playground-html@1.5.4:
+  version "1.5.4"
+  resolved "https://registry.yarnpkg.com/graphql-playground-html/-/graphql-playground-html-1.5.4.tgz#82752ec4ee36c62d64ccebf7d3ca47477c213bb6"
   dependencies:
     graphql-config "1.1.7"
 
-graphql-playground-middleware-express@1.5.3:
-  version "1.5.3"
-  resolved "https://registry.yarnpkg.com/graphql-playground-middleware-express/-/graphql-playground-middleware-express-1.5.3.tgz#5fd5c42d5cba8b24107ececfaf4e6b68690551fe"
+graphql-playground-middleware-express@1.5.6:
+  version "1.5.6"
+  resolved "https://registry.yarnpkg.com/graphql-playground-middleware-express/-/graphql-playground-middleware-express-1.5.6.tgz#db3c4b0ab5fd999cd9ed0ee16460dca321878afd"
   dependencies:
-    graphql-playground-html "1.5.2"
+    graphql-playground-html "1.5.4"
 
 graphql-playground-middleware-lambda@1.4.0:
   version "1.4.0"