creater migration to remove BlacklistController

app/scripts/migrations/021.js

@@ -0,0 +1,33 @@
+const version = 21
+
+/*
+
+This migration removes the BlackListController from disk state
+
+*/
+
+const clone = require('clone')
+
+module.exports = {
+  version,
+
+  migrate: function (originalVersionedData) {
+    const versionedData = clone(originalVersionedData)
+    versionedData.meta.version = version
+    try {
+      const state = versionedData.data
+      const newState = transformState(state)
+      versionedData.data = newState
+    } catch (err) {
+      console.warn(`MetaMask Migration #${version}` + err.stack)
+    }
+    return Promise.resolve(versionedData)
+  },
+}
+
+function transformState (state) {
+  const newState = state
+  delete newState.BlacklistController
+  return newState
+}
+