chore: update deps

Author: achingbrain

package.json

@@ -47,7 +47,7 @@
     "chai": "^4.2.0",
     "dirty-chai": "^2.0.1",
     "lodash": "^4.17.11",
-    "memdown": "^4.0.0",
+    "memdown": "^5.1.0",
     "multihashes": "~0.4.15",
     "multihashing-async": "~0.8.0",
     "ncp": "^2.0.0",
@@ -63,16 +63,16 @@
     "datastore-fs": "~0.9.0",
     "datastore-level": "~0.12.0",
     "debug": "^4.1.0",
-    "err-code": "^1.1.2",
-    "interface-datastore": "~0.7.0",
+    "err-code": "^2.0.0",
+    "interface-datastore": "^0.8.0",
     "ipfs-block": "~0.8.1",
     "ipfs-repo-migrations": "~0.1.0",
-    "just-safe-get": "^1.3.0",
+    "just-safe-get": "^2.0.0",
     "just-safe-set": "^2.1.0",
     "lodash.has": "^4.5.2",
     "p-queue": "^6.0.0",
     "proper-lockfile": "^4.0.0",
-    "sort-keys": "^3.0.0"
+    "sort-keys": "^4.0.0"
   },
   "license": "MIT",
   "contributors": [