fix: never return Node.js Buffers

With updating the dependencies, we now never return Node.js Buffers

There were cases where CIDs where returned as Node.js Buffers. Now all
CIDs are returned as Uint8Array only.

Fixes #126.

package.json

@@ -36,14 +36,14 @@
   },
   "dependencies": {
     "class-is": "^1.1.0",
-    "multibase": "^3.0.0",
-    "multicodec": "^2.0.0",
+    "multibase": "^3.0.1",
+    "multicodec": "^2.0.1",
     "multihashes": "^3.0.1",
-    "uint8arrays": "^1.0.0"
+    "uint8arrays": "^1.1.0"
   },
   "devDependencies": {
-    "aegir": "^25.0.0",
-    "multihashing-async": "^2.0.0"
+    "aegir": "^26.0.0",
+    "multihashing-async": "^2.0.1"
   },
   "engines": {
     "node": ">=4.0.0",