Upgrade levelup from ~4.1.0 to ~4.2.0 (#132)

greenkeeper[bot] · vweevers · commit 98b58cb2dfce · 2019-09-08T20:29:37.000+03:00
diff --git a/package.json b/package.json
@@ -20,7 +20,7 @@
     "encoding-down": "~6.2.0",
     "level-compose": "^0.0.2",
     "level-js": "~4.0.0",
-    "levelup": "~4.1.0",
+    "levelup": "~4.2.0",
     "memdown": "~5.0.0",
     "tempy": "^0.3.0",
     "uuid": "^3.3.2"
