feat: packageFiles and PR information insert to elasticsearch

[zbyufei]

I have finished adding the function packageFiles and PR information insert to elasticsearch

1. add insert function in https://github.com/renovatebot/renovate/blob/master/lib/workers/repository/index.ts
2. add elasticsearch in https://github.com/renovatebot/renovate/tree/master/lib/util
3. update WriteUpdateResult to include pr data information

elasticsearch index mapping such as:

name	type
gitName	string
datasource	string
packageFile	string
depName	string
updateType	string
currentValue	string
fromVersion	string
toVersion	string
oldMajor	number
oldMinor	number
newMajor	number
newMinor	number
newValue	string
prId	number
prStatus	string
prUrl	string