Update encoding-down to the latest version 🚀 (#629)

* chore(package): update encoding-down to version 6.0.0

* fix test: encoding-down now rejects nullish values

Author: greenkeeper[bot]

package.json

@@ -33,7 +33,7 @@
     "concat-stream": "~2.0.0",
     "coveralls": "~3.0.2",
     "delayed": "~1.0.1",
-    "encoding-down": "^5.0.0",
+    "encoding-down": "^6.0.0",
     "hallmark": "~0.1.0",
     "level-community": "~3.0.0",
     "memdown": "^3.0.0",

test/batch-test.js

@@ -290,9 +290,17 @@ buster.testCase('batch()', {
 
     'test batch#put() with missing `value`': function () {
       // value = undefined
-      this.batch.put('foo1')
+      assert.exception(this.batch.put.bind(this.batch, 'foo1'), function (err) {
+        if (err.name !== 'WriteError') { return false }
+        if (err.message !== 'value cannot be `null` or `undefined`') { return false }
+        return true
+      })
 
-      this.batch.put('foo1', null)
+      assert.exception(this.batch.put.bind(this.batch, 'foo1', null), function (err) {
+        if (err.name !== 'WriteError') { return false }
+        if (err.message !== 'value cannot be `null` or `undefined`') { return false }
+        return true
+      })
     },
 
     'test batch#put() with missing `key`': function () {