* Upgrade geth from 1.8.15 to 1.8.18
* Update vat_tune to use shared repository methods
* Query blockchain by block hash instead of block number range
* Remove hash validation from repositories
* Fix vow flog integration test
* Update README Travis build sticker
* Update constants formatting per go fmt
* Update EthPublicKeyParser.ParsePublicKey to use discv5.PubkeyID method
* Address PR comments
- Delete header on conflict to prompt data refresh (cascade deletes all
data associated with that block)
- Derive header hash from rpc payload rather than computing it from data
(prevents hash mismatch between blockchain and cache)
* Use shared repo tests for vat_init
* Use shared methods in vat_init repository
* Use shared repo tests for vat_move
* Use shared methods in vat_move repository
* Use shared repo tests for vat_slip
* Use shared methods in vat_slip repository
* Use shared repo tests for vat_toll
* Use shared methods in vat_toll repository
* Use shared methods in vat_tune repository
* Use shared repo tests for vow_flog (+small namespace fix)
* Use shared methods in vow_flog repository
* Go vet + tiny oopsie
