fix migration so it doesn't error out on existing devices

migrations/migrate-tools.js

@@ -0,0 +1,16 @@
+const pgp = require('pg-promise')()
+const _ = require('lodash/fp')
+
+const settingsLoader = require('../lib/settings-loader')
+const machineLoader = require('../lib/machine-loader')
+
+module.exports = {migrateNames}
+
+function migrateNames () {
+  const cs = new pgp.helpers.ColumnSet(['device_id', 'name'], {table: 'devices'})
+
+  return settingsLoader.loadLatest()
+  .then(r => machineLoader.getMachineNames(r.config))
+  .then(_.map(r => ({device_id: r.deviceId, name: r.name})))
+  .then(data => pgp.helpers.update(data, cs))
+}