chore: update dependencies to released versions

multihashing-async and ipfs-repo have been released with a promised-based
API, use those.

Author: vmx

package.json

@@ -35,9 +35,9 @@
     "cids": "~0.5.7",
     "dirty-chai": "^2.0.1",
     "ipfs-block": "~0.8.0",
-    "ipfs-repo": "zcstarr/js-ipfs-repo#master",
+    "ipfs-repo": "~0.27.0",
     "lodash": "^4.17.11",
-    "multihashing-async": "multiformats/js-multihashing-async#feat/async-iterators",
+    "multihashing-async": "~0.7.0",
     "ncp": "^2.0.0",
     "promisify-es6": "^1.0.3",
     "rimraf": "^2.6.3"