fix(package): update ipfs-unixfs-exporter to version 0.37.3

Closes #2073

Author: greenkeeper[bot]

Diff for: package.json

@@ -119,7 +119,7 @@
     "ipfs-multipart": "~0.1.0",
     "ipfs-repo": "~0.26.5",
     "ipfs-unixfs": "~0.1.16",
-    "ipfs-unixfs-exporter": "~0.36.1",
+    "ipfs-unixfs-exporter": "~0.37.3",
     "ipfs-unixfs-importer": "~0.38.5",
     "ipld": "~0.21.1",
     "ipld-bitcoin": "~0.1.8",