added tenant + graph support

package.json

@@ -25,6 +25,7 @@
         "ioredis": "^3.2.2",
         "joi": "^13.4.0",
         "lodash": "^4.17.10",
+        "luxon": "^1.2.1",
         "mongodb": "^3.0.10",
         "performance-now": "^2.1.0",
         "uuid": "^3.2.1"
@@ -38,8 +39,10 @@
         "@types/ioredis": "^3.2.8",
         "@types/joi": "^13.0.8",
         "@types/lodash": "^4.14.109",
+        "@types/luxon": "^0.5.3",
         "@types/mongodb": "^3.0.19",
         "@types/uuid": "^3.4.3",
+        "graphql-playground-html": "^1.6.0",
         "graphql-playground-middleware-express": "^1.7.0",
         "nodemon": "^1.17.5",
         "prettier": "^1.13.4",