chore: update contributors

Author: daviddias

package.json

@@ -52,5 +52,14 @@
     "multihashes": "^0.2.1",
     "xtend": "^4.0.1"
   },
-  "license": "MIT"
-}
+  "license": "MIT",
+  "contributors": [
+    "David Dias <daviddias.p@gmail.com>",
+    "Francisco Baio Dias <xicombd@gmail.com>",
+    "Lars-Magnus Skog <ralphtheninja@riseup.net>",
+    "Pau Ramon Revilla <masylum@gmail.com>",
+    "Stephen Whitmore <stephen.whitmore@gmail.com>",
+    "dignifiedquire <dignifiedquire@gmail.com>",
+    "greenkeeperio-bot <support@greenkeeper.io>"
+  ]
+}