Reorganize smart contract types, udate eth tests, etc.

- Move smart contract constants and structs for variables to
  common/{ethrollup.go, ethauction.go, ethwdelayer.go}:
    - This removes repeated code of the structs for variables
    - Allows reusing the constants and variables from all modules without
      import cycles
- Remove unused common/scvars.go
- In common.BlockData, split data from each smart contract into a sepparate
  field (Rollup, Auction, WDelayer).  This affects the structures that til uses
  as output, and HistoryDB in the AddBlockSCData.
- In Synchronizer:
    - Pass starting block of each smart contract as config, instead of
      incorrectly using the genesis block found in the acution constant (which
      has a very different meaning)
    - Use variable structs from common instead of an internal copy
    - Synchronize more stuff (resolve some TODOs)
    - Fix some issues found after initial testing with ganache
- In eth:
    - In auction.go: Add method to get constants
    - Update README to use ganache instead of buidlerevm as local blockchain
      for testing
    - Update env variables and test vectors to pass the tests with the
      deployment in the ganache testnet.
    - Use ethereum keys derived from paths (hdwallet) in testing to avoid
      hardcoding private keys and generate the same keys from a mnemonic used
      in the ganache tesnet.

cli/node/cfg.buidler.toml

@@ -0,0 +1,37 @@
+[StateDB]
+Path = "/tmp/iden3-test/hermez/statedb"
+
+[PostgreSQL]
+Port     = 5432
+Host     = "localhost"
+User     = "hermez"
+Password = "yourpasswordhere"
+Name     = "hermez"
+
+[L2DB]
+SafetyPeriod = 10
+MaxTxs       = 512
+TTL          = "24h"
+
+[Web3]
+URL = "http://localhost:8545"
+
+[Synchronizer]
+SyncLoopInterval = "1s"
+    [Synchronizer.StartBlockNum]
+    Rollup = 1
+    Auction = 1
+    WDelayer = 1
+
+[SmartContracts]
+Rollup   = "0xD6C850aeBFDC46D7F4c207e445cC0d6B0919BDBe"
+Auction  = "0x038B86d9d8FAFdd0a02ebd1A476432877b0107C8"
+TokenHEZ = "0xf4e77E5Da47AC3125140c470c71cBca77B5c638c"
+TokenHEZName = "Hermez Network Token"
+
+[EthClient]
+CallGasLimit        = 300000
+DeployGasLimit      = 1000000
+GasPriceDiv         = 100
+ReceiptTimeout      = "60s"
+IntervalReceiptLoop = "200ms"