Set up CLI framework

[austinabell]

Sets up ethermint CLI framework to be connected to logic implemented in future PRs. Defaults include commands for checking status of daemon rpc, setting up keys, and setting up config for the daemon. Here is the output for the base command:

Ethermint Client

Usage:
  emintcli [command]

Available Commands:
  status      Query remote node for status
  config      Create or query an application CLI configuration file

  keys        Add or view local private keys

  help        Help about any command

Flags:
      --chain-id string   Chain ID of tendermint node
  -e, --encoding string   Binary encoding (hex|b64|btc) (default "hex")
  -h, --help              help for emintcli
      --home string       directory for config and data (default "/Users/austinabell/.emintcli")
  -o, --output string     Output format (text|json) (default "text")
      --trace             print out full stack trace on errors

Use "emintcli [command] --help" for more information about a command.

Doesn't include setting up query, tx, rest api routes (Cosmos SDK server for cli alternative), and web3 API commands. As we discussed, starting the web3 rpc server should go through the CLI so I added the todo there.

Implements #5