Ethereum integration. (v2.0)

- [x] [Add eth node's health to /api/admin]()
- [x] [Add internal -> external transactions]()
- [x] [Fix dialyzer picking up wrong build path for :db app]()
- [x] [WIP: Receiving blockchain transactions]()
- [x] [Add Ethereum connectivity status to /api/admin]()
- [x] [Geth test integration]()
- [x] [Add nonce handler]()
- [x] [Add reference links to API responsibilities]()
- [x] [Add ability to generate ERC20 tokens]()
- [x] [Move balance parsing logic to eth_blockchain]()
- [x] [Fix private key generation]()
- [x] [Create cold wallet references]()
- [x] [Web3 integration]()
- [x] [Blockchain wallet page]()
- [x] [Advanced filtering for transactions]()
- [x] [Management endpoints for blockchain wallets]()
- [x] [Handle Ethereum transactions]()
- [x] [Eth blockchain transaction]()
- [x] [Ethereum Multi-Node Interface]()
- [x] [Add 2FA support via authenticator]()
- [x] [Retrieve blockchain balance]()
- [x] [Retrieve balances on the blockchain for given tokens flag/ethereum integration]()
- [x] [Add blockchain wallet schema]()
- [x] [Blockchain wallet schema]()
- [x] [Geth ethereum node communication]()
- [x] [Ethereum Node Communication (with Geth adapter)]()
- [x] [Ethereum account generation in eWallet]()
- [x] [Set up staging Geth cluster]()
- [x] [Ethereum Node interface project]()
- [x] [ERC-20 token import]()
- [x] [Ability to retrieve blockchain transactions details]()
- [x] [Add a page to interface with cold wallets: metamask, ledger]()
- [x] [Turn an existing internal token to an ERC-20 token]()
- [x] [Create ERC-20 token]()
- [x] [Import ERC-20 token]()
- [x] [Update Token and add ETH generating module]()
- [x] [Add nonce GenServer to allow transaction chaining.]()
- [x] [Add endpoint to create cold_wallet reference]()
- [x] [Move balance parsing logic from geth subapp to eth subapp]()
- [x] [Support 2FA in admin panel]()
- [x] [Run geth with tests (`mix test --geth`)]()
- [x] [List blockchain wallets (hot + cold) + see balances]()
- [x] [Handle blockchain transaction in transfer modal]()
- [x] [Update transactions to show Ethereum ones]()
- [x] [Add a way in the admin panel to generate an Ethereum deposit address for each wallet.]()
- [x] [Prepare blockchain token minting]()
- [x] [Refactor EthBlockchain Adapter]()
- [x] [Support lower and upper case for blockchain addresses]()
- [x] [Prepare blockchain call for minting of blockchain tokens]()
- [x] [Save and process all blockchain addresses in lowercase]()
- [x] [Add ability to deposit funds from hot wallet to OmiseGO Network in Admin Panel]()
- [x] [Pad private keys before encoding and storage ]()
- [x] [Fix passing boolean-incompatible value throwing error on `mix omg.config` ]()
- [x] [Passing an integer when setting boolean settings crashes ]()
- [x] [Revert nonce if a blockchain transaction returned an error ]()
- [x] [Refactor blockchain transactions ]()
- [x] [Extract `transaction` into `blockchain_transaction` ]()
- [x] [Adjust nonce value if transaction gets rejected by the network ]()
- [x] [Move funds to hot wallet after deposit]()
- [x] [Blockchain settings]()
- [x] [Add blockchain settings]()
- [x] [Setup listener for hot wallet on boot]()
- [x] [Consolidate blockchain transaction listener lifecycle]()
- [x] [Add childchain settings]()
- [ ] [Validate token blockchain status]()
- [ ] [Refactor: Move plasma deposit transactions to new table]()
- [ ] [Support sending MoreVP transactions from Admin Panel]()
- [ ] ["Cannot get connection id for node" error during start up]()
- [ ] [Prevent blockchain transaction for tokens that are not confirmed]()
- [ ] [Handle minting of blockchain tokens]()
- [ ] [Handle token blockchain status]()
- [ ] [Integrate Potterhat into eWallet]()
- [ ] [Send transactions events to websocket channels]()
- [ ] [Blockchain network statistics: gas price and wait time]()
- [ ] [Add blockchain setting in Configuration page]()
- [ ] [Update tokens pages to handle ETH + ERC-20 tokens]()